Technical Bulletin 218 March 1956

The Nearctic Chaoborinae (Diptera: Culicidae) 1tt.1'SITY OF t,JtNr, ~~~ ~ ~ AGRICULTUf? · ., /ARR 419 ~.r'>i Lion,~:' •. Edwin F. Cook ll1"£ OF AGRl•:1r'~ Department of Entomology and Economic Zoology •

University of Minnesota Agricultural Experiment Station CONTENTS Page 3 Introduction Acknowledgments 4 The external morphology of Chaoborus americanus (Johannsen) ...... 4 5 The adult . The head 5 The mouthparts 6 7 The thoraii:, ... The thoracic appendages 10 The ~pclorflfm and its appendages 11 11 T.he terf\'!nalia of the male . The termi~alia of the female 12 The fo.!=Jrth instar larva .. 12 The head 13 The thorax and abdomen .... 14 14 II The pupa Taxonomy of the Chaoborinae .... 15 Consideration of the techniques used 15 16 Keys The genus Chaoborus 20 The subgenus Chaoborus . 20 Chaoborus (Chaoborus) americanus (Johannsen) 20 Chaoborus (Chaoborus) flavicans (Meigen) 23 Chaoborus (Chaoborus) borealis new species 25 The subgenus Schadonophasma Dyar and Shannon 28 Chaoborus (Schadonophasma) nyblaei (Zetterstedt) 28 The subgenus Sayomyia Coquillett . 31 Chaoborus (Sayomyia) punctipennis (Say) 32 Chaoborus (Sayomyia) astictopus Dyar and Shannon 35 Chaoborus (Sayomyia) albatus Johnson 38 Chaoborus (Sayomyia) annulatus new species 39 The genus Mochlonyx Loew . 41 Mochlonyx velutinus (Ruthe) 44 Mochlonyx cinctipes (Coquillett) 46 Mochlonyx fuliginosus (Felt) 48 The genus Eucorethra Underwood 50 Eucorethra underwoodi Underwood 53 The genus Corethrella Coquillett .. 55 Corethrella brakeleyi (Coquille!!) . 58 Corethrella appendiculata Grabhorn 60 Corethrella laneana Vargas 62 Figures 65 Literature cited . 99

Submitted for publication October 20, 1953. 31\!-7-55 The N earctic Chaoborinae (Diptera: Culicidae)

Edwin F. Cook1

lntrodudion

THE CHAOBOIUNAE are a small subfamily of the medically and economically significant family Culicidae. As "poor rela­ tions" of the biting mosquitoes they have been largely neglected b:v taxonomists. Chaoborinae are small ( 1 A to 10.00 and Lil'nk (19.54), indicates that the lar­ mm.). delicate flies usually of a pale yel­ ,·ae of Chaoborinae consume large num­ low, grey, or brown color. They have short bers of the larvae of biting mosquitoes. mouthparts and are not known to bite; Since these insects are of direct value in accordingly they are often termed nonbit­ the natural control of mosquito popula­ ing mosquitoes. The wing venation is typi­ tions and since there is much confusion cally culicid. in the systematics of the group as it oc­ Only one North American species is curs in North America, a revisional study considered to be a nuisance. This is the has long been needed. Clear Lake gnat, Chaoborus (Sayornyia) This revisional and anatomical study a8tictopus Dyar and Shannon. This insect lays a necessary foundation for further in­ has appeared in tremendous swarms in the vestigations concerning the ecological in­ summer months along the shores of Clear terrelationships between the non biting and Lake. California, causing great annoyancP the biting mosquitoes. and misery by its numbers alone. This study supplements l\Iinnesota .\s a consequence considerable work Technical Bulletin 126, The Mosquitoes of has been done on the biology of this spe­ 1l1innesota with Special Reference to Their cies: Lindquist and Deonier (19t2a, 1942h. Biolor7ies, treating the biting mosquitoes. and 19-13); Lindquist, Deonier, and Consequently, we now have a reasonably Hancey (1943) ; Lindquist and Roth complete systematic treatment of all the (1950, 19.51); Deonier (19!3); Herms :\Iinncsota mosquitoes. 119:l7). The subfamily is composed of some 75 It is known that the larvae of these known species which are grouped into uonbiting mosquitoes feed on the larvae seven genera. The genera Prornochlonyx, of the biting mosquitoes and, consequently, Cryophila, and Neochaoborus arc not pres­ ,•xert considerable control on the numbers ent in the Neartic. In this revision four of lhose insects. The actual extent of the genera on\~· will be considered: Core­ natural control thus exerted has not been thrella. Chaoborus, Pr1ochlonyx, and Eu­ invPstigatcd to any extent, but personal rorethra. <'Xperience in rearing one of the species, Dyar and Shannon in a paper on the along with recent observation by Sailer North American Chaoborinae (1924)

1 Assistant Professor, Department of Entomology and Economic Zoology, University of Minnesota.

3 stated that while much work had been This species has been selected as our ref­ done up to that time on the biting Culi­ erence species, not necessarily because it cidae, "very little attention has been paid is the most typical species of the subfam­ to the American nonbiting forms, the ily, but largely because it is quite abun­ Chaoborinae and Dixinae." This situation dant and adequate quantities of all stages still prevails; since the publication of the are readily obtained. It is typical, how­ work by Dyar and Shannon only a very ever, of the genus Chaoborus and conse­ few papers have been published on thP quently is a good representative to whirh North American members of this group. other members of the subfamily can be There has been no adequate treatment related and compared. of the morphology of either the larvae or the adults in the American literature to date. Studies of the anatomy of the lar­ ACKNOWLEDGMENTS vae have been only briefly presented (Jo­ hannsen, 1903, 193.t; Felt, 1904; Knab, An acknowledgment of sincere apprecia­ 1909; Herms, 1937; and Deonier, 19±3). tion is due to the following individual., The adults have been even more casually who so generously made available speci­ treated. The wing venation and the male mens for this study: Dr. Alan Stone, Bu­ genitalia of a very few species are the only reau of Entomology and Plant Quaran­ structures that have been investigated tine, U. S. Department of Agriculture; (Johannsen, 1903; Felt, 1904; and Mathe­ Dr. H. H. Ross, Illinois Natural History son, 19±4). Survey; Dr. Edward Kessel, California The European fauna has fared some­ Academy of Sciences; Dr. Paul Freeman, what better. The external anatomy of the British Museum (Natural History); J. H. adults of some European species has been Vockeroth, Canadian National Collections; described and figured by Martini (1929). B. C. Smith, Dominion Parasite Labora­ while Peus (1934) has presented some tory, Belleville, Ontario; Dr. Henry Diet­ aspects of the larval and pupal anatomy of rich, Cornell University; Dr. Kenneth several species. From a taxonomic view­ MacArthur, Milwaukee Public Museum; point the most important recent papers Dr. Jean Laffoon, Iowa State College; Dr. on this subfamily are those of Martini T. 0. Thatcher, Colorado A. and M. Col­ (1929) for the Palearctic; Edwards (1932) lege; V. D. Roth, Oregon State Col­ for the world; Lane (1942, 1953) for the lege; Dr. P. D. Hurd, University of Cali­ Neotropic; and Matheson (1944) for fornia; Dr. Marion E. Smith, University North America. of Massachusetts; Dr. Don Rees, Univer­ The first part of this paper is devoted sity of Utah; Dr. J. T. Medler, University to a detailed study of the external mor­ of Wisconsin; Dr. R. E. Pfadt, University phology of the adult and immature stages of Wyoming; Dr. J. N. Belkin, University of Chaoborus americanus (Johannsen). of California at Los Angeles.

The External Morphology of Chaoborus americanus (Johannsen} A knowledge of the external morphol­ lows. The interpretation of the external ogy of the immature and adult stages is morphology here presented follows very the first step necessary in the segregation largely that proposed by Ferris (1939 et and definition of species, genera, or other seq.) and his students, Henry (1948) and natural assemblages of organisms within Cook (19°14 et seq.). Except where other­ any group under investigation. Hence, wise noted the anatomy of all species of this section is intended to form the basis Chaoborus is essentially identical with for the taxonomic consideration which fol- C. americanus.

4 THE ADULT foramen magnum and has obscured all evidence of primitive segmentation (fig­ Chaobor'Us (Chaobor'Us) amerzcan'Us ures IC, 2B). This "postgenal bridge" (Johannsen) is a relatively small, pale (Imms, 1944) separates the posterior ten­ "·cllowish-brown to dark brown, delicate torial pits from the maxillary cardines by appearing culicid with short mouthparts. a solid band of sclerotization. Primitively, The size is quite variable: 3.00 to 7.10 the posterior tentorial pits lie in the pre­ mm. body length for females and 5.50 to maxillary sutures, according to Ferris 8.00 mm. for males. In general appear­ (1942, 1943, 1944). ance, the members of this species resemble The eyes and antennae are located on t"·pical culicids, except for the short the ocular-antenna! segment. The eyes are mouthparts. large, somewhat rcniform, and well sepa­ The Head rated in both sexes. The antennae are typically culicid. Figures 1, 2, and 3 These are made up of (1) a small, ob­ The head capsule externally resembles scure, ringlike first segment or scape, I hat of "the mosquito" (Matheson, 1944, which is bare of setae, (2) a large globu­ page 6) . It consists very largely of the lar pedicel, which is bare of setae in the o('ular-antennal or third segment with lit­ males but has six to eight setae in the ! le evidence lo indicate the inclusion of females, and (3) a terminal flagellum of anr of the posterior segments that sup­ 13 segments, each of which bears a whorl po,sedly constitute a portion of the primi­ of long setae in the male and a shorter, tive head capsule. somewhat more sparse whorl in the female. There is no coronal suture present, al­ The diameter of the male pedicel is ap­ though there is a wide, pigmented, medial proximately 1.8 times that of the female. stripe extending from the cervical mem­ The antennae are not illustrated. linme forward to a termination between The tentorium is well developed (figure the antenna! foramina. This coronal stripe 1 B). The anterior pits are located laterally i.s demarked by shallow lateral furrows. in the semi-membranous areas between The anterior portion of this coronal the head capsule proper and the forward stripe expands into a median pigmented projecting clypeal sclerite. The tentorial spot between the antenna! foramina. This arms pass through the head from the an­ spot will be here designated as the "frontal terior pits to the posterior pits. The pos­ rnacula" (figure IA). The terms "coronal terior pits are smaller than the anterior stripe" and "frontal macula" are topo­ and are located at the lower margin of the graphical terms and have no morphological foramcn magnum. t--ig-nificance. Projecting anteriorly from the head fn the female, the antenna! foramina are capsule proper is the well defined clypeal surrounded by a wide membranous area sclcrite (figures IA, IB). This sclerite is which begins at the inner margin of the made up of the clypeus in part, but the eyes on either side and extends across the ocular-antenna! segment has also contrib­ whole, of the area between the foramina uted to its structure. This is evident from from below the frontal macula to the pos­ the presence of the anterior mandibular ar­ lC'rior margin of the clypeal sclerite. In ticulation on the margins of the sclerite, the male, the antenna! foramina are almost about midway along its length (figures \\rice the size of those in the female and IA, 8A, SC). 0 <'cupy most of this central membranous The anterior mandibular articulation in area. the Neuropteroid orders is (according to Posteriorly there are no sutures in either Ferris, 19-13 and Cook, 1943) to the para­ s,•x lo indicate the presence of any seg­ clypeal lobe. This lobe is a part of the ment other than the ocular-antenna!. Ven­ ocular-antenna! segment often separated trally, the head capsule sclerotization has from the segment by the tentorial pit or a C'Xpanded to form a bridge below the suture or sinus leading to the tentorial pit.

.5 The clypcal sclerite forms the dorsal their normal position, fit firmly against the wall of a proboscis or rostrum. Ventrally, medial surfaces of the labellae. The oral the rostrum is membranous. The mem­ face of the labrum is membranous with branous ventral portion probably contains the exception of a very slender median elements of the segments posterior to the strip of sclerotization and two somewhat third segment. wider lateral strips which are continuous The posterior mandibular articulation is posteriorly with the selerotizcd margins to the margin of the cibarium at relatively of the cibarial cavity. the same level as the anterior articulation The mandibles are short, thin, well sclc­ (figures 3A, 3C) . This indicates that the rotized but transparent structures which cibarium has developed as a result of the articulate to the elypcal sclerite anteri­ inflexion of the circum-oral area, includ­ orly and to the wall of the cibarial cavily ing at least the ventral remnants of the posteriorly (figures 2C, 3A, 3C). l\fancli­ mandibular segment. bles are present and similar in both sexes. The chaetotaxy of the head is as fol­ According to Crampton (19-12), mandibles lows: Some variation is present in the dif­ in the Diptcra occur in the males of onlc· ferent species of the genus, and where this two species of Simuliidae, in one specie., occurs it will be indicated in the specific of Ceratopogonidae, and as abnormalities descriptions. The vertex is thickly beset in a few male Culicidae. with long setae in both sexes. The frontal The maxillae (figures IC, 2A) are di­ macula is bare of setac in the males, while rectly comparable to the maxillae present the females have from two to seven setae. in the JYiecoptcra and the more primiliw The occipital setae extend beneath the Ncmatocera (for example, Anisopodi­ foramen magnum. The clypeus, premen­ dae). For a comparison see Crampton tum, and maxillary palpi are covered with (1942), Ferris (1942), and Imms (19-H). long and short setae, and the labellae arc The cardines or articulatory sclerites of beset with short setae. the maxillae articulate with the postgenal bridge of the head capsule as in Panorpa The Mouthparts c01nmunis (Imms, 194-1; text figure IA) Figures 2A, 2C, 2D, and 3 and Phlebotomus argentipes (ibid.; text The most evident structural difference figure 11). between C. americanus (or the Chaobori­ The stipes is a long, slender, S-shaped nae in general) and the Culicinae is ap­ sclcrite present in the surface membrane parent in the mouthparts. The same struc­ on the posterior side of the rostrum, plus tures are present in each, but in the Chao­ a seta-bearing, sclerotized lobe localed at borinac the various appendages are much the distal end of and slightly detached less elongate. According to all authors the from the S-shaped sclerite. This semi­ Chaoborinae are nonbiting. As far as the detached lobe simulates the palpifer or literature is concerned there is apparently a basal palpal segment. Actually the lobe no information based on observation of is neither of the latter structures since the the feeding habits of the adults, but it first segment of the palpus proper articu­ should be pointed out that the Chaobori­ lates directly to the expanded distal por­ nac have all of the structures necessary tion of the S-shapcd sclerite or to the main both for piercing and for feeding on fluid.~. body of the stipcs and not to this stipitnl The labrum (figure 2D) is elongate, ap­ lobe. proximately twice as long as wide, and The maxillary palpi are four-segmented. one-half the length of the clypeus. It is as has alreadv hePn indicated by Edwards largely membranous with a slender band (19:l 02). The· cndite lobe of ·the stipcs of sclerotizalion across the upper anterior (galca of Cramplon, 1912; lacinia of Imms. margin from which another slender sclero­ 19 J.1.) articulates with the distal end of tized strip projects anteriorly lo the lip. the main body of the stipes (S-shapcd At the distal end of the lahrum there sckrile) just mesacl of the articulation of is a pair of membranous lobes which, in the maxillary palpus. The lacinia is slightly

6 longer than the mandible, blade shaped, on the sclerotized lateral margins of the and well sclerotized. The tip bears a group cibarium about midway along its length. of short, stout setae. The double articulation of the mandible The labium (figures IA, IB, IC, 3B) seems to be unique among the Diptera. is comparable to that of the more primi­ Robinson (1939) shows a single articula­ tive Nematocera and the Mecoptera. The tion (the anterior) in Anopheles maculi­ mentum (postmentum of Imms, 1944) is pennis; Ferris (1942) found only one in completely membranous and lies between Blepharoceridae; Nicholson (1945) found the slender stipites of the maxillae. The only one in Simuliidae; and Snodgrass distal sclerotized part of the labium is the (1944) apparently found but a single an­ enlarged prementum. This prementum is terior articulation in those Diptera which divided longitudinally by a median suture. he examined. The labellac (labial palpi) are two-seg­ mented and articulate with the outer an­ tcriormosl margins of the prementum. The Thorax A small, triangular, basally sclerotized Figures 4, 5, 6, 7D and apically membranous plate lies on the The head is attached to the thorax by a ,·cntral side of the distal end of the pre­ rather slender neck (figure 7D). The sup­ mentum between the latter and the label­ porting elements are the paired cervical lae. A similar structure is present in the sclerites. There have been no extensive Dixidae, the Culieinae, and several other studies of this area aside from that of ncmaloeeran Diptera. Snodgrass (19-H) Crampton (1926). considers this to be the ligula in mosqui­ Each cervical sclerite is composed of toes. Imms (1914) terms the structure the three sclerotized plates. The anterior plate "median labial process" and believes that of each sclerite is triangular in shape and it is not the ligula. Aside from its position, articulates with the head on a pair of tl1ere are no criteria available which will small processes at the upper outer margin aid in homologizing this structure with of the foramen magnum. known structures in other insects. The posterior plates are also triangular The hypopharynx (figures 3A, 3C) is a in outline. These articulate with the thorax stout. well sclerotized stylet bearing short just beneath the pronotal lobe at the in­ set ac distally. This structure serves as the ner anteriormost edge of the procpister­ ,·cntral closure of the anterior portion of num. This is the same point of articulation the oral cavity. In cross section the hypo­ shown in the Tipulidae (Rees and Ferris, pharynx is V-shaped and is continuous l939) and in the Diptcra illustrated by posteriorly with the floor of the cibarium. Crampton (19-f.2). The median plates are Tl1e salivary duct opens into the floor of connected to each other by a bridge of this Val the base of the hypopharynx. sclerotization passing beneath the neck. The cibarium (figures 3A, 3C) has a The prothorax (figures 4A, 4B, 5, 6A, heavily sclerotized floor. The Yentral scle­ 6B) is yery much reduced in size. Its rolization extends around the margins of structure is comparable to that shown in the cibarium and for a short distance over the illustrations of the thorax of the Culi­ th<· dorsal surface. Beyond this marginal einae figured by Crampton (19°12), Komp .sclcrotization, the dorsal surface of the (19'.37). and Dyar and Shannon (1924). cibarium is wholly membranous. Heavy A pair of anterior lobes lies at either muscle bundles originating on the clypeal side of the anterior end of the enlarged .seh•ri le insert on the dorsal surface of the mesothoracic scutum. These lobes arc the ciharium so the whole structure is an remnants of the anterior part of the pro­ dficimt-appearing cibarial pump. notum which have been forced to either At least part of the cibarium is formed side from their primitive position by the from the inflexed circmn-oral region. This hypertrophy of the mesothoracic tergum. c<:ntention is supported by the presence The anterior pronotal lobes are connected of lhe posterior mandibular articulations to each other dorsall? by a narrow sclero-

7 tized collar anterior to the scutum of the cussion of this region in any of the better mesothorax. known works on the Culicidae. There are, Caudad of the anterior pronotal lobes consequently, certain errors in the termi­ (according to Freeborn, 1924), the pos­ nology applied to the thoracic sclerites of terior pronotum has been divided into two the Culicidae. In any case, the terminolog~­ lateral sclerites. The anepisternum is a of the Culicinae cannot be applied to the distinct but much reduced sclerite lying Chaoborinae. ventrad of the pronotal lobes and cephalad The author has not had sufficient time of the posterior pronotum. to investigate the Culicinae in any detail. The pleural suture is quite short, ex­ but a hasty examination of Anopheles tending from the coxal condyle to the walkcri seems to bear out this contention. margin of the posterior pronotum. The It should be indicated that the author is pleural apophysis extends the full length in complete agreement with Ferris (19--10) of the suture. and Michener (19--14) in regard to the Another well defined suture passing just composition of the thoracic region of in­ cephalad of the anterior spiracle serves sects in general and the sternal region m to mark the posterior boundary of the pos­ particular. terior pronotum from the apex of the pro­ If the ventral surface of the thorax of pleural suture to the mesothoracic scutum. C. mnericanus is examined (figure 4B), a Immediately posterior to this suture, be­ pair of small sclerites can be seen lying low and posterior to the mesothoracic mesad of the bases of the prothoracic spiracle, lie two sclerotized plates, one pos­ coxae. These paired sclerites are separated terior to the spiracle and one ventrad of it. from each other by a median suture, the These sclerites are separated from each discriminal line. These sclerites are the other by a well defined suture which ex­ katepisterna since they bear the ventral tends from the suture posterior to (mor­ coxal condyles. Hence, the structure which phologically ventrad of) the posterior pro­ has been known as the episternum (or notum just below the spiracle to approxi­ propleuron, according to some authors) is mately the middle of the pleural cleft. in actuality the anepisternum of the pro­ In the "typical culicid" illustrated by thorax. Posterior to the paired katcpi­ Crampton (1942, figure 6D) the posterior sterna lies a small median sclerite, which or upper plate is called the anterior anepis­ is the secondarily developed sternum. ternum. Komp (1937, figure 1) calls this The mesothorax (figures 4A, 4B, 5) is plate the mesanepisternum. However, both the largest thoracic segment. The meso­ authors leave the lower part, ventrad of notum or scutum forms the greater part the postpronotum, unnamed. Freeborn of the dorsal region of the thorax. The . (1924) calls both plates the anepislernum lobelike, rather triangular scutellum lies of the mesothorax; yet he clearly shows immediately caudad of the scutum. On in his illustrations of Dixa clavata (1924, either side of the scutellum and extending figure 3) that the anterior plate is located down to the notal wing processes are the anterior to the spiracle. parascutellar sclerites (Crampton, 194'2). By all of the available criteria this lower Posterior to the scutellum is the postno­ sclerite can only be the proepimeron (or tum, which is somewhat larger than the cpimeron I) . In the first place, it lies im­ preceding sclerite and constitutes practic­ mediately posterior to the pleural suture. ally all of the remainder of the dorsum. Secondly, it lies morphologically ventrad The sclerites of the pleural region can of the posterior pronotum. Thirdly, it is be directly homologized with those in the separated from the area bearing the an­ rest of the Culicidae, but some correction terior or second spiracle by a well defined of the terminology must be first under­ suture. taken. The chief landmark is the pleural As far as the author can discover, the suture, which extends from the lateral sternal n·gions of the Culicidae have never eondyle of the mesothoracic coxa to the been investigated. At least there is no dis- pleural wing process. The suture forms a

8 deep phragma for the whole of its length. of Michener). Then the so-called "sterno­ The pleural apophysis arises in the pleurites" of culicidologists or "katepi­ lower part of the pleural suture somewhat sterna" of more morphologically inclined dorsad of the coxal condyle (figure 5) . This workers must be the preepisterna. apophysis is a double invagination. The Separating the preepisternum from the anterior invagination is merely a deepened more dorsal elements is a complex com­ part of the pleural suture, while the pos­ bination of suture, membranous cleft, and terior is in the form of a crescent, in­ phragma. This is apparently homologous rnginating from the body wall a short with the pleural cleft in the neuropterans, distance caudad of the first. This sec­ Agulla adnixa, as described by Ferris and ondary invagination or phragma joins the Pennebaker (1939), and Plega signata, as primary both dorsally and ventrally, form­ described by Ferris (1940). This cleft ing thereby an area within the body cavity separates the preepisternum from the ,d1ich is closed off from the rest of the anepisternum above. body cavity on all sides except mesally. The anepisternum in this species and Just vcntrad of the pleural apophysis in many other Culieidae is divided into is a small sclerotized plate which bears two sclerites, an anterior and a posterior, the lateral coxal articulation. This sclerite by a well marked intra-anepisternal suture. i.s separated dorsally from the main por­ The anterior anepisternum, which is fairly tion of the epimeron by a phragma which well sclcrotized, lies just posterior to the fuses along its inner margin with the spiracle and dorsad of the proepimeron. lower margin of the pleural apophysis and The posterior anepisternum has been extends from the pleural suture to the termed the prealar area or prealar knob coxal condyle. From its position, this scle­ by most culicidologists. Morphologically ri te is the katepimeron of the mesothorax. such a term is meaningless although topo­ The area dorsad of the latter sclerite graphically it has value. is the anepimeron rather than the mesepi­ One other landmark should be located. meron, as culicidologists have termed it. This is the prealar apophysis which in­ Posterior to the coxal articulation, the vaginates from the apex of the intra­ mcron is present as a well sclerotized but anepisternal suture. small sclerite that is largely concealed by The metathorax (figures 4A, 4B, 5) is the eoxa. quite reduced. The metanotum is a nar­ Before the anterior pleural regions can row sclerite which passes over the dorsum he discussed, we must consider the sternal between the bases of the halteres. The n·gion of the mesothorax (figure 4B) . postnotum of the mesothorax has pushed There can be discerned a pair of small beneath this metanotum in its posterior ,·entral sclerites, which are partially sepa­ expansion so that the metanotum more rated from each other by a median fold or less covers the posterior part of the and suture. This median line is not as postnotum. complete as is the median line in the pro­ A seemingly unique structure occurs thoracic region, but it is apparent. in all of the members of this genus that These small plates bear the ventral coxal have been examined. This is a pair of articulations and are separated anteriorly small fingerlike processes, thickly beset from the so-called sternopleurites by dis­ with small fine setae, located on the me­ tinct sutures. The median line or suture is tanotum on either side of the midline. the cliscriminal line. The sternal apophysis These will be referred to as the "metanotal arises in its exact center. Following the processes." concept of the insect thorax expressed by The pleural suture in this segment is Ferris (1940) and by Michener (19-14), in the form of a shallow phragma which the small sclerites just described can only lies practically at the posterior extremity he the katepisterna. The suture lying of the thorax. It extends from the pleural anterior to them must be the "pleural articulation of the coxa along the margin l'osta" of Ferris (1940) ("precoxal suture" of the thorax about one-third of the

9 distance to the dorsum and there turns notum, the proepisternum, preepisternum, sharply inward and follows a rather sinu­ anepisternum, the upper part of the me­ ous course to the pleural wing process sepimeron, and the parascutellum. Except (haltere). for the parascutellars, which are absent ·when the metathorax is viewed from in Sayomyia and Schadonophasma, these the ventral side, we again find the small setae are present in varying numbers in all paired katepisterna separated by the dis­ species. All species of Chaoborus have the criminal line bearing the ventral coxal whole of the thorax covered with mrcro­ articulations. The katepisterna are con­ setae with the exception of the vittae tinuous as thin sclerotized strips around noted above. the front of the coxae, with the small The Thoracic Appendages plates lying just dorsad of the metathor­ acrc coxae. Figures 7, 8, VA_, VC Since there is no evident suture (pleural The wings (figure 9C) are well de­ costa) between the ventral element and veloped and possess a typically culicid the dorsal element above the coxa, it is venation. The wing veins bear what ap­ probable that the dorsal element is merely pear under examination with a light micro­ a part of the katepisternum. This dorsal scope to be but slightly modified setae. part has been termed the "metaeuster­ However, electron micrographs2 of these num" by Komp (1937) and the "meta­ "setae" reveal that they have the struc­ meron" by Carpenter et al. (1946). The ture of scales. Around the posterior border anepisternum is separated from the katepi­ of the wing there is also a fringe of long sternum by the pleural cleft. The epimeron lanceolate scales, which electron micro­ is exceedingly narrow ventrally but be­ graphs reveal to have typical scale struc­ comes wider above the sharp inturning of ture. These lanccolate scales occur in t,rn the pleural suture. Dorsally it is bounded sizes, the shorter approximately one-half by the metanotum. the length of the longer. The wing mem­ To return to the ventral area once more, brane is, in addition, covered with typical there arises from the posterior part of the culicid microtrichia. There is no profound discriminal line a pair of distinct sternal difference between the basal articulatory apophyses, which are not united with the sclerites (figures SA, SB) of this species pleural apophyses. These metathoracic and that of the more generalized pattern sternal apophyses differ from the mcso­ of articulations illustrated by Snodgrass thoracic apophyses in this detail and also (19'.l.5). in the fact that they are separate all the The halteres can be understood by ref­ way to their common base. erence to figure 9A. The homology of the As far as ornamentation of the thorax halteres with an unmodified wing is readily is concerned, the mesoscutum is marked apparent if one examines the basal portion with two pairs of dark brown to black or scabellum. The axillary sclerites can be vittae (figure 6C). which indicate the seen lo correspond quite closely with tho,c origins of the thoracic muscles. These vit­ present in unmodified wings. The capitn­ tae are present in all species of the sub­ lum is large and somewhat spherical, and family and are characterized by the com­ it bears on the mesa! surface three or four plete absence of micro- and macrosctae. sctae. The entire surface of the midhallerc The remainder of the mesoscutum bears and capitulum is covered with microsctac. long setae in the pattern indicated in The legs present no unusual features, figure 6C. The scutellum bears two or as can be ascertained by reference lo three irregular transverse rows of long figure 7. The coxae are stout and short. setae, and the postnotum is bare. The coxae of all three thoracic legs bear There are present, in addition, long some selae arranged in a fairly definite sctae on the pronotal lobes, the postpro- pattern, as shown in the illustration. The

2 The author is indebted to Dr. A. Glenn Richards for tlie electron micrographs of these wing-s and the interpretation tlaereof.

10 prothoracic and metathoracic coxae also posterior and lateral margins of each bear patches of very minute setae on their sclerite. The exception is tergite 1 in which caudal margins. The prothoracic coxae the posterior row is medial. possess a lateral and a mesa! patch, and The abdominal spiracles are quite mi­ the metathoracic coxac a lateral patch. nute, but they can be discerned in the The remaining segments have no fea­ membrane between the ·tergites and ster­ t.mes of note. The first tarsal segment is nites in the anterior half of each segment. slightly less than one-half the length of the tibia. All the segments are covered The ·rerminalia of the Male rather densely with both long and short, Figures 9B, 9D slender setae. The third tarsal segment The eighth segment is unmodified in the of the mesothoracic leg of the female has male but is only one-fourth as long as on the caudal surface a series of short segment 7. The ninth is the first seg­ setae, slightly stouter than the rest, ar­ ment actually involved in the genitalie ranged in the form of a comb. structures. The ninth tergite is well de­ The last tarsal segment bears a pair of veloped and somewhat triangular in out­ .,mall claws, on which a number of small line, and it bears two dorso-lateral lobes sdae are located basally, and a pair of on each of which are from 9 to 11 setae. ,:daceous pulvilli approximately one-half The sternite is less well developed, form­ the length of the claws. There is no em­ ing simply a narrow collar of sclerotiza­ podium. The metathoracic leg is the long­ tion around the morphologically ventral L'.sl, with the prothoracic leg two-thirds but topographically dorsal side of the apex a, long and the mesothoracic leg two-fifths of the abdomen. This collar is deeply as long. emarginate posteriorly. Following the interpretation of Mich­ The Abdomen and Its Appendages ener (1944a) (see also Gustafson, 1950), The pregenital segments of the abdo­ the gonocoxites arise from the posterior men (figure lOD) are quite simple in lateral margins of the ninth segment. The structure. They are composed simply of a gonostyles articulate with the apical por­ krgite and a slightly smaller sternite. In tion of the gonocoxites. In this species the this species the tergite of the first segment gonostyle is heavily sclerotized and bears is smaller than the succeeding tergitcs, a few scattered, minute setae but no ter­ and the first sternum is completely mem­ minal spine. branous. A pair of small appendagelike sclerites There are eight pregenital segments in lies between the gonocoxites on either both males and females. The chief differ­ side of the genital orifice. Dyar and Shan­ ence evident between the structure of this non (19!2-1) termed these the "tenth ster­ area in the two sexes is one of proportion. nites" and Edwards (193'2) indicates that In the male the tergites are almost equal they are probably the parameres. These in length and breadth, while in the female structures articulate to the bases of the the tergites are almost twice as wide as coxites and are moved by muscles which long, thus correlating with the greater originate within the coxitcs; therefore they width of the female abdomen. cannot be "tenth sternites." The term In both sexes the abdominal segments "paramerc" means so many things to dif­ and the intcrscgmental membranes are ferent authors that this name is imprac­ covered with minute microsetae with the tical to use. Following Michener (1944a) exception of small, paired, bare spots on still, the musculature and the point of at­ the tergites of segments 3 through G. tachment indicate that they are the penis These spots appear as pale, roughly circu­ valves. lar patches on the tergites when viewed The penis valves articulate to the mor­ under low magnification. The tergites and phologically mesovcntral edge of the an­ slPrnites of both sexes bear numerous long terior· margin of the gonocoxites. Apically selap in well clefined rows oceurring at the tlwy lie free of the surface membrane on

11 either side of the genital orifice. There is This view is apparently not held by no obvious penis, merely a membranous Gerry or Gjullin and certainly not by lobe. The penis valves have a very charac­ Crampton (1942). In the Tipulidae figured teristic form in different species and are, by Rees and Ferris (1939) the gonopore therefore, of considerable taxonomic im­ obviously lies between 8 and 9. There­ portance. fore, there is no reason why the so-called The postgenital segments are not de­ cowl should not be the reduced ninth veloped in the male. The anus simply sternite rather than some secondarily de­ opens through the apical, membranous veloped structure. lobe which bears the genital orifice. Mor­ The postgenital segment (segment J 0) phologically the anus is dorsal to the geni­ is large and bilobed and bears the paired tal orifice, but topographically, owing to cerci. The cerci in all Chaoborus species rotation of the terminal segments, the anus are beset with short setae. The anus opens is ventral. Edwards (1932) in his diagnosis through a cleft between the two lobes of of this subfamily indicates "hypopygium the tenth segment. not inverted." As far as this species is The spermathecae are three in number, concerned, this is not true, nor is it true of spherical, and well pigmented. The sper­ any other member of the genus Chaoborus mathecal ducts are sclerotized and pig­ that the author has seen. mented for a short distance from the point of union with the spermathecae. The Terminalia of the Female In this species these ducts are always curved and lie parallel to the surface of Figures JOA, JOB, JOG the spermathecae for the full length of the In the female genitalic complex, seg­ pigmentation. ment 8 is likewise unmodified. In seg­ ment 9 the tergite is somewhat bilobed posteriorly, each lobe bearing approxi­ THE FOURTH INSTAR LARVA mately nine rather long setae. Ventral and posterior to sternite 8 (in the area Figures 11, 12 called the atrium by culicidologists) , The curious form and structures of the there are three openings. The most pos­ larvae of the Chaoborinae in general and terior of these is, at least in part, the Chaoborns in particular have been dealt spermathecal duct opening. The next an­ with by vanous authors: Weismann terior opening could not be traced but may (1866), · Meinert (1886), Johannsen represent an accessory gland pore. The (1903), Felt (1904), Knab (1908), Pcus gonopore is the largest and most anterior (1934), Eckstein (1936), Hermes (1937), opening. and Deonier (1943). There is no need, Posterior to the pore of the spermathe­ therefore, to stress the wide di vergencc cal duct there is a small, transverse, slen­ of the larvae of Chaoborinae from the der sclerite (probably homologous to the remainder of the Culicidae. "cowl" of the Culicinae), which is closely C. americanus is long (10.00 to 13.00 joined laterally to a pair of small triangu­ mm.), slender, and practically transparent. lar sclerites. According to Gerry (1932) It lies horizontally in the water when at and Gjullin (1937) this cowl is the ninth rest (figure 12A). The tracheal system is sternite. Edwards (1941) indicates that represented by one pair of air sacs in tl~e this cowl is not sternite 9 in the Culi­ thorax and another slightly smaller pair cidae but that the true ninth sternite is in the seventh abdominal segment. No represented by a small plate (the insula) spiracles are present. References to papc~s anterior to the atrium in some Culicidae. concerned with these air sacs and their He bases this on the assumption that the probable function as hydrostatic organs gonopore of the females in this family lies in the Chaoborinae can be found in the between segments 9 and 10 and not be­ bibliography of Wesenberg-Lund (1943) · tween 8 and 9. There is no siphon present, although ac- cording to Peus (1934) a "siphon vesti6e" Schremmer (1950) has made an inter­ is supposedly present. esting case for the theory that this is not Phylogenetically to select this species as the labrum in Chaoborus but is actually representative is to start at the wrong end the epipharynx or a structure of the of the evolutionary series; the structures palatum or roof of the cibarium. How­ of the larvae of this species-or of the ever, he does not take into account the genus Chaoborus-cannot be fully ex­ nature of the homologous structure in the plained without reference to some of the larYae of M ochlonyx and Eucorethra. In Jllore generalized species of the subfamily the latter two genera (figures 22, 27) the as, for example, M ochlonyx velutinus. fact is eyident that the appendage at­ tached to the anterior margin of the cly­ The Head peus is the labrum. In the latter two gen­ era the antenna! foramina haYe not be­ The head (figure 11) is elongate and come approximated so as to obscure the compressed laterally. Posteriorly there is homology. faint indication of the coronal and clypeo­ Between the clypeus and labrum in lrontal sutures (figure llA), but beyond 1W ochlonyx are setae which are probably this there are no intersegmental sutures on homologs of those setae in Chaoborus the head capsule. Anteriorly the head cap­ which are termed postantennal filaments. rnlc is drawn out into a long, deep, pro­ The tip of the labrum of M ochlonyx hoscislike structure, which bears at its possesses both bifurcate and three-tined apex the closely approximated antennae setae as in Chaoborus. The palatal surface (figures llB, llC). of the labrum of M ochlonyx bears a pair A short, longitudinal, median suture of setal fans which have the form and hctween the antenna] foramina extends structure of those present at the apex of two-thirds of the distance to the eyes. the labrum of Chaoborus. For these rea­ Tl11s may indicate the infolded remnant sons it is believed that this structure is oi the clypeus which has been reduced the labrum and not the epipharynx. , oncomitant with the mesal approxima­ The tentorium (figure llB) consists of tion of the antennae. a pair of very slender rods which pass from Ventrally and topographically caudad a point just anterior to the anterior man­ hul morphologically anterior to the an­ dibular articulations through the head to tennae is a cluster of five pairs of long the lateral margins of the foramen mag­ sPtac which have been termed the "post­ num at a ]eye) slightly above the simple antennal filaments" by Johannsen (1934) or larval eyes. (figure llB). Immediately posterior to There are two pairs of eyes (figure llB) these setae are two flat, bladelike, anteri­ in the last instar larva, a pair of large, orly serrate setae which have been termed incompletely developed adult eyes lo­ the ·'prelabral leaf-like appendages" by cated anteriorly and a pair of small, simple Felt (1904) (figures llB, 12D). larval eyes located close behind. Topographically posterior to this is the The mouthparts are much reduced, and reduced and simplified labrum. This bears only the mandibles of the true oral ap­ t lm~e small setae on its aboral surface and pendages appear large enough to serve is covered at the apex by a dense imbri­ as feeding organs. In these larvae the an­ cation of short, stout, flattened, apically tennae (figure llB) have become modi­ bifurcate setae. On either side of the apex fied in structure and function to serve also of the labrum there are two pairs of setal as feeding organs or at least as organs of fans (figure 1 lB). These correspond in prehension. Each antenna consists of a position lo the messorial fans of the Culi­ single, long, stout segment. At the apex c·inac, hut there are no other criteria by this bears five stout, curved, bladelike 1d1ich these can be identified in this spe­ setae, four long and one somewhat shorter. cies since the musculature of the labrum The longer setae are approximately equal is much reduced. in length to the antenna itself.

13 The mandibles (figure rnE) are well According to Peus (1934) this is the developed. They have at their outer an­ vestige of the siphon of other Culicidae. terior corner a fan of :2:2 to :29 stout, It should be pointed out, however, that curved, bladelike setae about one-half as the annulation on which this "siphon ves­ long as those of the antennae. On the tige" occurs has a musculature which indi­ outer posterior angle of each mandible cates that it is a segment. This then is there are three stout, heavily sclerotized segment 9, and the siphon occurs on seg­ teeth. These teeth are preceded by one ment 8. Thus, the term "siphon vestige" short and two long, slender, unmodified seems to be inaccurate. setae and two small spines. Each mandible The anal segment (figure rnF), poster­ articulates to the head capsule anteriorly ior to segment 9, is a composite struc­ just beneath the anterior tentorial pit and ture formed by the fusion of the remain­ posteriorly to the lateral "·all of the head ing body segments. Ventrally the anal immediately anterior to the maxilla (figure segment bears a row of :23 to :26 long, llB). pectinate setae. This row is homologous to The maxillae (figure rnC) are consider­ the ventral brush of other Culicidae. ably reduced. Each consists of a flat, some­ At the posterior end of the anal seg­ what curved, lobelike stipes and a small, ment are four short, acutely pointed pa­ fingerlike, laterally placed process which pillae, above which is a cluster of four is the maxillary palpus. This palpus bears pcctinate setae. In these structures the a single apical seta, and the stipes bears correspondence to the Culicinae is ver;y two widely spaced small setae. close. Ventrad of the anal papillae is a The labium (figure rnB) is even further structure not present in the Culicinae, the reduced. It consists of a small, median, "anal apparatus" (Peus, 1934). The area somewhat sagittate plate-the submcntum around the anal opening is expanded to (Cook, 1949)-which has a pair of small form a terminal lobe which passes around sctae at its apex and a very small, pos­ the ventral side of the anus. This bears teriorly rounded prementum. At the apex ventrally and medially two flat, anteriorly of the prementum is a minute pair of two­ directed, hooklike processes (figure l:2G). segmented labial palpi. The salivary duct Extending laterally and dorsally from opens into the cibarial cavity immediately the ventral hooks around the outer mar­ anterior to the prementum. gins of the anal lobe is a series of flattened processes (figure rnH) . The processes arc The Thorax and Abdomen of two sizes which alternate with each The thorax offers little for discussion. other. The whole apparatus can be re­ It is composed of the three thoracic seg­ tracted and drawn within the anal open­ ments inlimatclv fused into a single en­ ing. This complex structure has probably larged unit located immediately posterior been modified from originally paired anal to the short, slender cervical region. It prolegs such as are present in the Chiro­ bears numerous, more or less segmentally nomidae. arranged, multiple setae, much as in other Culicidac. These setae are so transparent THE PUPA as to be very difficult to detect. Figures 18A, 18B, 18C The eight succeeding abdominal seg­ ments offer no more by way of structural The morphology of the pupa of this features than does the thorax. Each seg­ species will not be discussed to any con­ ment is beset with several plumose setae. siderable extent since there are few ex­ Near the posterior end of segment 8 there ternal features that warrant such discus­ is a slight constriction that sets off a sion and since there has been but little small annulation from the anterior part of morphological investigation of the pupae the segment (figures rnA, rnF) . A slight of insects in general. conical protuberance is present on the dor­ The pupa of this species resembles the sal side of this small posterior annulation. pupae of the Culicinae. The eephalothorax 14 is smaller relative to the total size of the quite short. There are setae on the ab­ body, constituting something less than dominal segments which are useful in the one-third of the total length. The thoracic separation of some of the species examined. respiratory horns (figure ISC) differ from These will be referred to under the specific those in the Culicinae in that they are descriptions. ,pindleshaped, and each possesses a nar­ The caudal end of the pupa bears a pair row, slitlikc opening which is located on a of paddleshaped appendages (figure ISA). small papilla at the distal end of the horn. These paddles are strengthened laterally The surface of the respiratory horn is by a pair of marginal ribs, the inner con­ closely reticulated. spicuously serrate for the distal three­ The abdomen is relatively longer than fourths of its length, and the outer very in the Culicinae and hangs straight down inconspicuously serrate on the distal rather than curving forward beneath the fourth. There is in addition a median rib ccphalothorax. The seventh segment of the which has a branched seta at the middle. abdomen (figure ISB) is longer than the The membrane between these ribs is quite preceding segments, while the eighth is thin and transparent.

Taxonomy of the Chaoborinae

CONSIDERATION OF THE wi_ng Ie~gth (W.L./W.W.) TECHNIQUES USED wmgw1dth wing length -c-----c-~----'-c,--- (W.L.jPf.L.) The following measurements have been length of profemur found to be of value in this study and In addition, in the males the following will be included for each species: head are used: \1idth (H.W.), width between eyes at the narrowest point on the facial aspect length of gonocoxite (C L S (\Y.B.E.), clypeus length (C.L.), premen­ length of gonostyle o. ·/ t.L.) tum length (P.L.), wing length from the tip to the incision distal to the alula length of penultimate antenna! segment (W.L.), and wing width at the distal end length of ultimate antenna! segment of Cu~ (W.W.). (Pu.L./U.L.) The following ratios have also been For the sake of brevity, the symbols in found useful: parentheses following these expressed ra­ tios and measurements will be used hence­ forth. head width . ! h b (H.W./W.B.E.) These measurements and ratios were w1c t etween eyes variable, but differences in the means and lack of overlap of range or small overlap head width (H.W./P.L.) of range were the criteria used in their prementum length selection. The specimens used for these measure­ head width l (H.W./C.L.) ments were slide mounted after having e ypeus length been cleared in 10 per cent KOH, stained with basic fuchsin when necessary, and wing le~1gth (W.L./H.W.) mounted in balsam. The wings were not head width treated with KOH.

15 Keys KEYS TO THE GENERA OF THE CHAOBORINAE Adults 1. First tarsal segment longer than second (figure 7 A) 2 la. First tarsal segment shorter than second (figure !'!OB) Mochlonyx (p. 41) 2. Anal vein terminates at or before fork of Cu (figure 25C) ; pedicel and ca­ pitulum heavily setaceous (figure 25B); claws with basal tooth (only one species) ...... Eucorethra (p. 50) !'!a. Anal vein terminates distad of fork of Cu (figure 9C) ; pedicel and capitu­ lum with few setae (figure 9A) or with numerous short setae (figure 30B); claws simple 3 3. R terminates closer to R than to Sc (figure 9C) ; pedicel and capitulum 1 2 with no more than 15 setae (figure 9A) ; claws all equal ..... Chaoborus (p. 20) 3a. R terminates closer to Sc than to R (figure SOC) ; capitulum with numer­ 1 2 ous short setae (figure 30B); claws on prothoracic legs of db un­ equal. ... Corethrella (p. 55)

Larvae 1. Eighth abdominal segment with no siphon or external trace of respiratory apparatus (figure 12A); head narrow; antennae approximate .. Chaoborus la. Eighth abdominal segment with siphon (figures 23A, 33A) or at least a prominent spiracular apparatus (figures !'!SA, !'!SC); head broad; antennae may or may not be approximate . 2 2. Antennae approximate; each ocular lobe with a transverse row of stout setae (figure 32A) ..... Corethrella !'!a. Antennae widely separated; no row of stout setae on ocular lobes (figures 22A, 27A) 3 3. Eighth abdominal segment with an elongate siphon; thorax and abdominal segment 7 with a pair of enlarged air sacs: terminal antennal setae as long as or longer than antennal segment (figure 23A) M ochlonyx 3a. Eighth abdominal segment with a short spiracular apparatus as in Ano­ pheles; no enlarged air sacs in thorax or abdominal segment 7; terminal antenna] setae shorter than antennal segment (figure !'!SA) Eucorethra Pupae 1. Terminal abdominal segment with movable, paddlclike appendages (figure, ISA, lSD, lSF, lSH, lSK, !'!SD) 2 la. Terminal abdominal segment without movable, paddlelike appendages (figures 34A, 34B) Corethrella 2. Thoracic respiratory horns trumpet-shaped, wide open at apex (figure !'!SF) ...... Eucorethra !'!a. Thoracic respiratory horns spindleshaped, tracheal opening small and slitlike (figure lSC) 3 3. Anal paddles with thin delicate membrane, reinforced by obvious ribs on each side and in middle (figure ISA) ...... Chaoborus 3a. Anal paddles with membrane rigid, no obvious marginal ribs (figure 23C) ...... M ochlonyx

1() KEY TO THE SUBGENERA OF Chaoborus Adults I. Wings spotted; legs with spots or rings; with or without well developed pulvilli; no parascutellar setae . 2 la. Wings clear; legs unmarked; pulvilli at least half as long as claws; para- scutellar setae present ...... Chaoborus s. str. (p. 20) 2. Pulvilli at least half as long as claws; males without a lobe or paired, stout setae on gonocoxites; penis valve with large clawlike head (figure I6J) (only one species) ...... Schadonophasma (p. 28) 2a. Pulvilli minute, less than one-fourth as long as claws; males with a lobe or paired stout setae on inner face of apical half of gonocoxites (figures 16A, 16C, 16E); penis valve with small head (figures 16B, 16D, 16F) .. Sayomyia (p. 31)

KEY TO THE SPECIES OF Chaoborus s. str. Adults I. Frontal macula of females with I to 6 setae (usually); prementum short, head width approximately 2.75 times prementum length or more; preapical spine of penis valve shorter than head of penis valve (figure 16G) 2 la. Frontal macula of females without setae; prementum longer, head width less than 2.6 times prementum length; preapical spine of penis valve as long as or longer than head of penis valve (figure 16H) C. flavicans (p. 23) 2. Postpronotum darkest at extreme upper margin and posterior angle; medial pronotal setae lacking in females; pleural apophyseal area without pigmen­ tation; capitulum ovoid; preapical spine of penis valve shorter than head, penis valve head large, spatulate (figure 161) ...... C. borealis n. sp. (p. 25) 2a. Postpronotum lighter at upper margin and around postpronotal setae, darker immediately below setae; medial pronotal setae numerous in females; capitulum spherical; pleural apophyseal area darkly pigmented; preapieal spine of penis valve minute (figure 16G) ...... C. americanus (p. 20)

KEY TO THE SPECIES OF SUBGENUS Sayomyia Adults 1. Adults with two large, indistinct brown patches on wings (figure 13H); femora and tibiae with a series of reddish-brown rings for their full length ...... C. annulatus n. sp. (p. 39) la. Adults with small discrete reddish-brown spots on wings at bifurcations and apices of veins and along veins; femora and tibiae may be spotted but never completely ringed with brown . 2 2. Legs without distinct spots; wings only faintly spotted; gonoeoxite of male without lobe; pale species. C. albatus (p. 38) 2a. Legs with distinct spots of reddish-brown . 3 :l. Setac of scutum and abdomen arising in reddish-brown spots or pinnaculae. East of the Rocky Mountains ...... C. punctipennis (p. 32) 8a. Setae of scutum and abdomen not located in reddish-brown pinnaculae. Pacific Coast states ...... C. astictopus (p. 35)

17 KEY TO THE KNOWN LARVAE OF Chaoborus I. Dorsal process of segment 9 apparently two-segmented (figure ISJ); mandibular tooth 2 without an attached tooth (figure l 7F); antenna with a spine on anterior face one-fourth distance from base (figures 17]\'I, 17N, 170); labrum with a pair of long setae on anterior face near middle (figure 17P) Subgenus Sayornyia 5 la. Dorsal process of segment 9 not two-segmented (figure 12F); antenna without a spine on anterior face or, if present, near distal end (figures 17J, 17K, 17L); labrum with short setae on anterior face near middle (figure llB) 2 2. Prelabral leaflike appendages less than 2.5 times longer than wide (figure 12D) ...... C. arnericanus 2a. Prelabral appendages at least four times longer than wide (figures 17A to 17E) :1 3. Antenna with seta on anterior face one-fourth to one-third distance from distal end (figure 17L); mandibular fan with 10 to 12 sctae C. flavicans 3a. Antenna without seta on anterior face (figure l 7J) 4 4. Mandibular fan with 13 to 20 setae; size large (15.00 to 19.00 mm.) ...... C. nyblaei (p. 28) 4a. Mandibular fan with ll to 12 setae; size small (10.00 to 11.00 ·mm.) ...... C. boreali., 5. Prelabral appendages seven times, or less, longer than wide (figure 17E) C. albatus 5a. Prelabral appendages 15 times, or more, longer than wide (figures l 7C, 17D) 6 6. Seta on anterior face of antenna .021 to .026 mm. long (figure 17M) ; cast of Rocky Mountains . C. punctipennis 6a. Seta on anterior face of antenna .034 mm. long (figure 17N) ; Pacific Coast .. C. astictopus The larva of Chaoborus (Sayornyia) annulatus is as yet unknown.

KEY TO THE KNOWN PUPAE OF Chaoborus 1. Lateral rib of paddle with a few serrations or teeth at apex . 2 la. Lateral rib of paddle without any trace of teeth or serrations .... 3 2. Median rib of paddle indistinct, bearing a plumose and a simple seta medially; lateral rib with at most two or three minute teeth at apex (figures 18H, 18K) 4 2a. Median rib of paddle distinct, a single plumose seta medially; lateral rib with seven to nine serrations (figure ISA) .. C. arnericanus 3. Median rib of paddle with a minute seta at apex (figure ISD); dorsum of seventh abdominal segment with four pairs of posterior setae (figure ISE) ..... C. flavicans 3a. Dorsum of seventh abdominal segment with three pairs of posterior setae and with one pair of lateral setae (figure 18G) ...... C. nyblaei 4. Inner or mesa] rib with numerous serrations on apical three-fourths of surface (figure ISH); median rib incomplete apically C. punctipennis 4a. Mesa! rib with very sparse serrations, only two or three on apical one- third of surface (figure ISK) ; median rib indistinct but complete ...... C. astictopus The pupae of C. borcalis, C. albatus, and C. annulatus are unknown.

18 KEY TO THE SPECIES OF Mochlonyx Adults I. \Vings pale to somewhat infuscated, wing scales unicolorous (figure 20F) 2 la. Wings mottled with patches of light and dark scales (figure 20E) ...... M. cinctipes (p. 46) 2. Proepisternal setae 6 to 13, posterior pronotal setae 3 to 15, upper mesepimeral setae 19 to 29, katepisternum 3 with a few setae; meta­ thoracic claws of male identical with those of prothoracic and mesothor­ acic M. velutinus (p. 44) 2a. Proepisternal setae 2, postpronotal setae 1, upper mesepimeral setae 3 to 5, no setae on katepisternum 3; pro- and mesothoracic claws of male with median and basal teeth, metathoracic claws simple .. M. fuliginosus (p. 48) Larvae and pupae of lJ/1. velittinus and 1l1. cinctipes indistinguishable; larva and pupa of M. fuliginosus unknown.

KEY TO THE SPECIES OF Corethrella Adults 1. Clypeus of both JJ and 'i''i' with numerous (20-30) setae; gonostyle with an apical seta (figure 31E) . C. laneana (p. 62) la. Clypeus with less than 10 setae; no apical seta on gonostyle . 2 Q. Head of both JJ and 'i''i' with a multiple row of setae mesad of eye margin posteriorly (figure 31D); gonostyle with a stout mesoproximal seta (figure 31C) C. appendiculata (p. 60) 2a. Heads of JJ and 'i''i' with a single row of setae mesad of eye margin posteri- orly (figure 29B); gonostyle with no mesoproximal seta (or a minute one) (figure 31A) ...... C. brakeleyi (p. 58)

Larvae I. Sutures bounding submentum parallel (figure 33C); abdomen without dorsal brown pigment patches ...... C. appendiculata la. Sutures bounding submentum divergent posteriorly (figure 32B); each abdominal segment with a median dorsal brown pigment patch (figure ~M 2 2. Setae of anal and dorsal brushes single ...... C. bralceleyi 2a. Setae of anal and dorsal brushes bifid ...... C. laneana

Pupae I. Respiratory horn constricted medially (figure 34C); abdominal tergite 7 without postero-lateral setae (figure 34A) ...... C. brakeleyi la. Respiratory horn not medially constricted (figures 34D, 34E); abdominal tergite 7 with a minute or long seta at each postero-lateral corner . Q Q. Tergite 7 with a long, conspicuous seta at each postero-lateral corner (figure 34B); respiratory horn short (.19-.21 mm.), broad near base (figure 34D) ...... C. appendiculata Qa. Tergite 7 with a minute seta near each postcro-lateral corner; respira- tory horn longer (.3·1 mm.), narrow at base (figure 34E) ...... C. laneana

1!J The Genus Chaoborus

Chaoborus Lichtenstein, 1800, Wiede­ pp. 43-44, pl. 15, fig. 148, pl. 18, figs. mann's Archiv. Zoo!. 1:174. Type: C. 168, 169, 170, 172. Matheson, 1944, A antisepticus Licht. = C. crystallinus Handbook of the Mosquitoes of North DeGeer 1776. America, Comstock Pub. Co., Ithaca. Corethra Meigen, 1803, Illigers Mag. II, N. Y., p. 95, pl. 10, fig. 3. 260. Type: C. lateralis Mg.= C. crys­ tallinus DeGeer. Not T. culiciformis Comments DcGeer [fide Edwards, 1920, 1930]. A considerable variation in absolute The genus Chaoborus Lichtenstein was size, color, and setaceousness is evident in divided into three subgenera, Chaoborus this species, and this variation is in part s. str., Schadonophasma Dyar and Shan­ correlated with geographical distribution. non, and Sayornyia Coquillett, by Dyar The larger, blacker, more setaceous speci­ and Shannon (1924). mens are usually found in the northern part of the range. THE SUBGENUS CHAOBORUS C. americanus is readily distinguished The subgenus Chaoborus in the Nearc­ from other species of Chaoborus by the tic is composed of species from 3.00 mm.- characters given in the keys. In addition, 8.00 mm. long. The wings are unmarked; the females have from 10-30 setae on the vein RS is long and may have a short spur median pronotal sclerite, whereas in C. (basally directed) at its base; vein Cu flavicans these setae are usually absent (7 5 runs to the hind margin of the wing or per cent of those examined) or no more almost there and is not spurred; vein An than six in number. In C. borealis these rarely attains the level of m-cu. The legs are entirely absent. are unmarked; pulvilli are distinct and ap­ This is a widespread species ranging proximately half as long as claws. One to across North America from the Atlantic three parascutellar setae are always pres­ Coast to the Uintah Mountains in Utah ent. The gonocoxites of the male are with­ and north into Alaska. The southern out a preapical lobe. The penis valves bear limits of its distribution are New Jersey a minute to large preapical spine. and southern Illinois. Larvae are found in small ponds of a semipermanent to permanent nature CHAOBORUS (CHAOBORUS) throughout the year. AMERICANUS (JOHANNSEN) Corethra plumicornis, var. americana Jo­ Description hannsen, 1903, N. Y. State Mus. Bui. MALE 68, pp. 395-397, pl. 39. Total length 5 ..50-8.00 mm. All setac Sayomyia americana (Johannsen), Felt, relatively uniform in color on any one 1904, N. Y. State Mus. Bui. 79, pp. specimen but vary from light yellowish­ 368-370, figs. 107-111. brown to black in different specimen,: Sayomyia hurlsoni Felt, 1904, ibid., pp. general body coloration light yellowish­ 371-374, figs. 112-113, pis. 13, 28, 40, ,17_ brown to black. Johannsen, 1934, Cornell Agr. Expt. Sta. Mem. 164, p. 44 (Chaoborus). II ead ( figure 2B) Chaoborus crystallina, Dyar and Shannon Head capsule light in color, darkened (not DeGeer), in part, 1924, Insecutor over vertex; pedicel dark brown to black, Inscitiae Menstruus 12:210. flagellar segments with dark basal ring. Chaoborus americanus (Johannsen), Ma­ dark at whorl, lighter apically; antenna] theson, 1925, Canad. Ent. 57:159. setae yellow to dark brown; lateral margins Edwards, l 932, Genera Insectorum, of clypeus somewhat infuscated· maxillarv Fasc. 194, p. 25. Johannsen, 1934, ibid., stipites, palpi, sclcrotized portio~s of labci- 20 lae all infuscated. Irregular double row of Abdomen (figure 14A) setae extending forward on either side of Ground color of abdomen light yellow­ postfrontal stripe; frontal macula bare. ish-brown to nearly black; anterior tergites Head width .89-1.05 mm.; width be­ darker than posterior two or three; first t.ween eyes .44-.64 mm.; length of premen­ sternite not developed in southern forms, lum .28-.37 mm.; length of clypeus .26-.33 slightly developed in far northern forms; mm.; penultimate antennal segment length first. tergite darker on anterior two-thirds; .\!3-.33 mm.; ultimate antennal segment second, third, and fourth tergites dark length .12-.23 mm.; H.W.jW.B.E. = 1.64- except for irregular pale band on anterior '2.08; H.W./P.L. = 2.95-3.38; H.W./C.L. = one-fourth; tergites 2-6 with paired pale ~.05-3.71; Pu.L./U.L. = 1.29-1.89. spots; some specimens with anterior cor­ Thorax (figures 4A, 6A, 6B, 60) ners of tergites 2-6 darker than remaining tcrgites. A longitudinal row of setae oc­ Thorax light yellowish to grey in ground curs between tergites and sternites. ('O!or with conspicuous darker areas (figure OA) . Anterior pronotal lobes uniformly Genitalia (figures 9B, 9D, 16G) darkened; posterior pronotum darker on Tergite 8 with numerous scattered setae; upper half, except around setae; vittae sternite with single row essentially. Ter­ dark brown to black; medial area of scu- gite 9 (located ventrally) produced api­ 1um darker in ground color than lateral cally into a triangular process, basally areas; seutellum, postnotum, anterior mar­ somewhat bilobed, each lobe bearing 9-11 gin of anterior anepisternum, lower two- long setae; sternite 9 much reduced. Gono­ 1hirds of preepisternum and area of pleural coxites uniform, pale yellowish-brown to apophysis all darkened. nearly black; gonostyles approximately :'\Iedial seta row of mesoseutum termi­ one-quarter shorter than gonocoxites, dark nating in a dense cluster of scales. Pro­ brown to black, strongly sclerotized; penis notal setae approximately 30-60; proepi­ valve (figure 16G) pale, transparent, with slernal setae 5-19; posterior pronotals 6-12; circular head (free apex) bearing a minute prcepisternal setae 3-10; anepisternals 12- preapical spine. Coxite length .48-.62 mm.; ~7; upper mesepimerals 10-22; parascutel­ style length .35-.50 mm.; Co.L./St.L. = lars 1-3. 1.22-1.45. Thoracic appendages FE:'11:ALE Wings (figure 9C) clear to slightly in­ fuscated; length 3.14-4.11 mm.; width .70- Total length 3.00-7.10 mm. The color 1.00 mm.; W.L./W.W. = 4.00-4.47; W.L.j pattern throughout as in males; general H.W. = 3.33-3.93. Lanceolate scales of coloration somewhat paler than associated ll'ing margin of two alternating lengths: males. .15-.17 mm. and .057-.071 111111. (measured TI ead ( figure 1) at apex of anal vein); scales longer at wing Chaetotaxy as in male, except frontal base; vein An terminates 0.16-0.56 mm. macula bears two to seven setae; pedicel short of the level of m-cu; r-m distad of with five to nine setae; membranous area Ill-CU. around antenna! bases white to somewhat Capitulum of haltere (figure 9A) nearly fuscous. Head width .89-1.07 111111.; width spherical, white or yellowish to infuscated, between eyes .-16-.57 mm.; prementum bearing two to five irregularly placed setae length .\!8-.37 mm.; clypeus length .26-.33 on outer face and one to three in a ver­ mm.; H.,Y.jW.B.E. = 1.86-2.14; H.W./ tical row on inner face. P.L. = 2.78-3.37; H.W./C.L. = 2.83-3.77. Legs (figure 7) unicolorous, light yellow­ Last two antenna! segments equal. ish-brown to dark grey-brown. Profemur 1.:39-2.07 mm.; protibia 1.74-2.18 mm.; Thorax lirsl protarsus .62-1.00 mm.; W.L./Pf.L. = Pleural apophyseal areas smaller and 1.!ll-2.22. Claws dark brown to black; pul­ less pigmented than in male; chaetotaxy l'illi pale yellowish-brown to dark brown. identical except there are 10-30 setae (fig-

!ll ure 6B) on medial pronotal sclerite imme­ two subocular, and one postocular; labrum diately cephalad of mesonoturn. with three pairs of small setae on anterior Thoracic appendages face; anterior face of labral apex imbri­ cated with short, stout, bifurcate sctac Wing length 3.14-4.44 mm.; width .92- plus two pairs of laterally located seta fans 1.37 mm.; W.L.jW.W. = 3.18-3.46; W.L.f or brushes; labral brushes with approxi­ H.W. = 3.40-4.11. Vein An somewhat mately 20 setae each, the most distal pair longer than in male, attains level of rn-cu with four pectinate sctae. l\fandibular fan to .24 mm. short of attaining this level; with 22-29 setae, 3-5 of anterior setae api­ r-rn and m-cu in line (equidistant from cally pectinate; mandibles (figures 12E. base). 171) with three major teeth, median tooth Legs somewhat shorter than in male; with large attached tooth which attains W.L./Pf.L. = 2.10-2.37; prothoracic leg level of posteriorrnost tooth at apex; pos­ .85-.92 as long as rnetathoracic; mesothor­ terior tooth with three or four small teeth acic .71-.75 as long as metathoracic. Ap­ on posterior margin. pendages otherwise as in male. Thorax and abdomen Abdomen (figu.re 10) Setae of thorax and abdomen largely Cerci light yellowish-brown to dark grey­ plumose, transparent. Abdominal segment brown, covered with short setae, one­ 9 (figure 12F) without an obvious dorsal fourth the length of cerci; spermathecae process; anal fan with 23-26 short-plurnose (figures l0A, 14H) heavily sclerotized and setae. pigmented, dark brown to black; diameter of sperrnathecae .06-.08 mm. PUPA (figures ISA, 18B, lSC)

LARVA (figures 11, 12) Total length J 0.00-11.00 mm. Cephalo­ Based only on U.S. specimens thorax one-fourth of total length. Color­ less and transparent as larvae. Respira­ Total length (last instar) 10.00-13.00 tory horn spindleshaped (figure JSC). mm.; larvae clear, practically transparent finely reticulated on surface; length .85- with a slightly yellow-green cast (opaque .97 mm. Abdominal tergite 7 with four white in alcohol) ; eyes dark purple; mar­ pairs of plurnose setae posteriorly and one gin of head capsule around mandibular pair laterally. Anal paddles with inner rib bases and foramen magnum dark brown; closely serrate for apical three-fourths: mandibles yellowish except tips of teeth lateral rib sparsely serrate on apical one­ dark brown; antenna] blades yellow-brown fourth. Median rib with a plumose scta to brown; tracheal air sacs covered with near middle. black pigment cells dorsally; anal fan setae yellowish to yellow-brown; anal teeth yel­ Specimens Examined lowish to brown; thoracic and abdominal setae colorless, transparent. Type ci, Cornell Exp. No. 1027, Sub. 718, Lake Forest, Illinois, 1900. Head (figure 11) Cotype ci, Cornell Lot No. 231, Sub. l I, Head length 1.00 to 1.30 mm.; antennae Lake Forest, Illinois, May 1901, Need­ (figure 17K) .50-.52 mm. long, no setae on ham. anterior face; long antenna] blades .42-.47 Cotype c;>, Lake Forest, Illinois. No further mm.; short blade .33-.35 mm.; postantcnnal data. filaments .1,9-.55 mm. long; prelabral ap­ Cotypes, 25 larvae, Lake Forest, Illinois, pendages (figure 12D) less than 2.5 times ;\fay 1901, Needham. longer than broad, irregularly long-serrate (All types in the collection at Cornell anteriorly, terminating apically in a single University, Ithaca, New York.) . long tooth, posterior surface smooth, In addition to this type series, speci­ length .20-.22 mm. mens have been examined from the fol­ Head capsule with seven pairs of plu­ lowing localities: Alaska: Tanana, Hurri­ mose setac-three dorsal, one subocellar, cane, 166 mi. north of Anchorage; May 27 to July 6. Colorado: Rabbits Ear Pass; penis valves of the males is quite marked, July 18. Illinois: Cottage Grove, Kieths­ so that if only the extremes were available burg; May 19-23. lowa: Ledges State Park, it might seem that two distinct species Dubuque; April 11 to June 23. Michigan: are involved (figure 16H). However, with Detroit. Minnesota: Ramsey Co., St. Louis an adequate sample of specimens aII in­ Co., Pine Co., Wyoming, Cushing; May 3 tergrades can be found, and it becomes to June 27. Montana: Glacier Park; May impossible to segregate individual speci­ 14. Manitoba: Baldur, Bird, Churchill; mens. Even this might not invalidate the June 21 to July I. Ontario: Ottawa; April possibility that two or more species are 27 to June 22. Quebec: Aylmer, Great involved except that both extremes and Whale River, Harrington Harbor; May 11 some intergrades have been found in single to July 2. Tennessee: Reelfoot Lake; Aug. homogeneous samples. Single specimens 14. Utah: Uintah Mts.; June 19. have been seen in which the penis valves Adult specimens examined, 435. differed widely from each other. This species has been found across the CHAOBORUS (CHAOBORU~ whole North American continent. Its southern limits are :Maryland, :Missouri, FLAVICANS (MEIGEN) central Colorado, and northern California. Corethra fiavicans J\1eigen, 1830, System­ It extends north from Belleville, Ontario matische Beschrcibung der bekannten to the MacKenzie River delta and into Europaischen zweifliigeligen Insekten Alaska. VI, p. 243. Larvae in North America have been Corethra albipes Johannsen, 1903, N. Y. taken in watcr-filJed road ruts, temporary State Mus. Bui. 68, p. 398. Felt, 1904, ponds, and smaII pools. N. Y. State Mus. Bui. 79, pp. 363-366 (Sayomyia). Dyar and Shannon, 1924, Description lnsccutor Inscitiae ]Ylenstruus 12:211 MALE (Chaoborns). Johannsen, 1934, CorneIJ Agr. Expt. Sta. Mcm. 164, p. 44. Total length 4.70-7 .00 mm. All setae rel­ Sayomyia rot11ndifolia Felt, 1904, ibid., pp. atively uniform in color with exceptions 266-268. Johannsen, 1933, ibid., p. 43. noted below. Setac practically colorless Chaoborus crystallina, Dyar and Shannon or slightly silvery-grey through light yel­ (not DeGeer), in part, 192,1, ibid., p. lowish-brown to brown on darker speci­ 210. Matheson, 1925, Canad. Ent. 57: mens; setac of legs and abdomen usuaily lii9. Johannsen, 193°1, ibid., p. 43. Ma­ pale; thoracic and head setac dark; general theson, 1944, A Handbook of the Mos­ body coloration pale grey or light straw­ quitoes of North America, Comstock yellow to dark brown. Pub. Co., Ithaca, N. Y., p. 95. llead Chaoborus el11thera Dyar and Shannon, In greyish or yellowish specimens ver­ 1924, ibid., p. 211. Edwards, 1932, Gen­ tex light brown; in dark specimens dark era Insectorum, Fasc. 194, p. 25. brown. Frontal macula, lateral margins of Chaoborus flavicans (Mcigen). Martini, clypeal sclerite, prementum, stipes, and 1929, in Lindner, Die Fliegen dcr Pala­ three basal segments of maxillary palpi carktischcn Region, Bd. 3, Fasc. ll, 12, darkened; pedicel and basal portion of each p. 5G. Edwards, 1930, Ent. Monthly flagellar segment infuscated. :\Iag. G/J:Hi3-16-1. Edwards, 1932, ibid., Head width .79-.89 mm.; width between p. '2G. Matheson, 19-14, ibid., p. 94. eyes .37-.4-1 mm.; length of prementum .3'2-.35 mm.; length of elypeus .28-.32 mm.; Comments length of penultimate antenna! segment Chaoborus fiavicans is more variable .'25-.26 mm.; length of ultimate antenna! lhan C. arnericanus in color and chaeto­ segment .l 7-.2G mm. H.W./W.B.E. = 1.81- laxy and especially in the genitalic struc­ '2.'28; H.W./P.L. = 2.27-2.63; H.W.jC.L. = tures of the males. The variation in the 2.5'2-2.94; Pu.L./TT.L. = 1.00-1.40. Q3 Thorax tergites and sternites fewer and smaller in Thorax pale fumose grey or light yellow­ size than in C. american'US. ish with light brown darkened areas to Genitalia (figure 16H) very dark grey with more extensive dark Tergite 8 with numerous scattered setae; brown areas. In lighter specimens only an­ sternite 8 with a single transverse row of terior pronotum, disc of scutum, scutellum, setac. Tergite 9 produced apically, basal and postnotum darkened; laterally, median lobes with seven to nine long setae. Gono­ area of postpronotum and lower two-thirds coxitcs uniform pale yellowish-brown or of preepisternum darkened. In darker spe­ greyish-brown to dark brown; gonostyles cimens ground color dark grey (unpig­ dark brown, strongly sclerotizcd with mented only around spiracles) , lateral sparse minute setae on mesa! face and sur­ margins of scutum somewhat paler than rounding apex; penis valves pale, trans­ disc and a slightly paler band extending parent, each with small, ovoid, apically from posterior spiracle to lower margin of acute or obtuse head that bears a preapi­ anterior pronotum. Pronotal setae 30-40 cal, clawlike spine longer than head. (approx.); proepisternals 2-9; posterior Coxite length .50-.57 mm.; style length pronotals 3-6; preepisternals 3-5; anepiste1·­ .41-.46 mm.; Co.L.jSt.L. = 1.04-1.32. nals 8-14; upper mesepimerals 3-11; para­ FEMALE scutellars 1-3. Total length 3.00-5.20 mm. Color pat­ Thoracic appendages tern, general coloration, and seta color as Wings clear; length 2.70-3.59 mm.; in male. width .68-.92 mm. W.L./W.W. = 3.65-4.2·1; Ileacl W.L./H.W. = 3.72-4.40; longer posterior marginal scales .168 mm. long, the shorter Setae of head more numerous than in .078 mm. long (measured at apex of An); male; setae of vertex extend anteriorly on termination of An .11-.I 9 mm. short of either side of frontal stripe in four or fin level of m-cu. irregular rows; no setae on frontal macula; Legs as in C. americanus except last pediccl bearing 5-10 setae. Head width .73- three tarsal segments sometimes slightly .82 mm.; width between eyes .30-.37 mm.; darkened. Profemur length 1.74-1.96 mm.; length of prcmentum .28-.35 mm.; length protibia 1.85-2.00 111111.; first protarsus .81- of clypeus .28-.34 mm.; H.W.jW.B.E. = .88 mm.; W.L./Pf.L. = 1.79-2.0G. 2.00-2.52; H.W./P.L. = 2.21-2.64; H.W./ C.L. = 2.25-2.6L Abdomen ( figure 14B) Ground color of abdomen pale yellow­ Thora.1: ish or grey to dark brown. In pale spe­ Somewhat paler than associated males, cimens first and second tergi tcs light pleural apophyseal area smaller, and some brown; third, fourth, and fifth tergites females ( one-fourth of those examined) with white or yellowish anterior one­ with one to six medial pronotal setae. fourth, followed by dark band of equal Thoracic appendages width, followed by lighter brown; sixth Wing length 2.70-3.88 mm.; wing width and seventh tergites light yellowish-brown. .81-1.18 mm.; W.L./W.W. = 3.07-3.39; First sternite undeveloped; sternites of re­ W.L./H.W. = 4.00-4.80. Vein An attains maining segments light yellowish-brown; level of rn-cu or surpasses it by up to .21 seta bases surrounded by brown ring. mm. Halteres with up to 10 setae on inner In dark specimens, pattern essentially face of capitulum. Legs somewhat shorter the same except light area on tergites 3 than in male. through 5 is only one-eighth total tergite length, darker band still apparent. In all Abclorncn specimens intersegmental membranes light Paired pale spots of abdomen not as yellowish. Paired, pale spots on tergites in­ conspicuous as in female C. americanus conspicuous but present. Setae between hut present. Spermathecae as in figure HL

24 LARVA 18D) with inner rib serrate for apical Total length (last instar) 9.00-12.65 three-fourths; lateral rib without any trace mm.; clear, practically transparent; eyes of serrations. Median rib with a plumose purple; posterior margin of head capsule, seta just distad of middle and a single minute seta apically. around foramen magnum and mandibular hases, brown; muscle origins showing through head capsule as grey spots; tips Specimens Examined of antennae and tips of mandibular teeth Type 'i' of C. albipes (Johannsen), Ithaca, brown; terminal setae or blades of anten­ New York, Aug. 1901. nae and postantennal filaments brown. Type J of C. rotundifolia (Felt), Karner, Tracheal air sacs covered with black pig­ New York, July 7, 1904. ment cells dorsally; anal teeth brown; all Topotypes of C. eluthera Dyar and Shan­ other structures (including setae) color­ non, Id, l'i', Potlatch, Idaho, June 20, less, transparent. 1907, J.M. Aldrich; 1 J, Potlatch, June Tlead 24, 1903, Aldrich. Five JJ and four 'i''i' from England and the Head length .90-1.29 mm.; antennae Channel Islands determined as C. fiavi­ !figure 17L) .56-.62 mm. long, a small cans by F. W. Edwards and Paul Free­ .,eta on anterior face of antenna one­ man. fourth to one-half from distal end; longer Specimens also examined: Alaska: Fair­ anlennal blades .56-.60 mm. long; shorter banks; May 24. Alberta: Bilby; June-July. blade .23-.31 mm. long; postantennal fila­ British Columbia: Kelowana, Aspen ments .58-.62 mm. long; prelabral append­ Creek; May 20-July 7. California: Alturas; ages (figure 17 A) 4.1 to 5.1 times longer August. Colorado: Ft. Collins, N. St. Vrain than broad, somewhat serrate anteriorly, Ck., Boulder Co.; Aug. 8-Sept. 7. Illinois: terminating in a long spine .25-.29 mm. Lake Forest, Zion, Dunes Park; June 14- long. July 20. Maine: Norcross; July 14. Michi­ Labrum with two pairs of setae on an­ gan: Livingston Co.; May 28. Minnesota: lcrior face; apical pair larger, conspicuous; Little Falls, Lake Vadnais, Hennepin Co., proximal pair smaller, inconspicuous. Seta] Itasca State Park; June 9-July 3 (larvae, armature of labral apex with only 12-15 Oct.). Missouri: St. Louis; l\Iay 12. New .,ctac for each of the lateral brushes; an­ Jersey: Delair; Sept. 22. New York: Ithaca terior face of labral apex imbricated with (adults and larvae), Ringwood Hollow, stout bifurcate setae. Clifton Springs; April 30-Aug. 3. North­ :\Iandibular fan with 9-12 setae; mandi­ west Territories: Reindeer Depot, Mac­ bles with three major teeth (figure 17H); Kenzie River delta; July. Oregon: Klamath median tooth with a small basal tooth, al­ Lake, Siltcoos Lake (larvae); July 24. On­ most between 2 and 3; posterior tooth tario: Belleville (larvae) . South Dakota: 11·ith small teeth on the posterior margin. Waubay; June 6. Washington: Pullman; Thorax and abdomen April. 1Visconsin: Madison; August 17 Abdominal segment 9 with a dorsal, (larvae). Wyoming: Platt Co.; July 12. posteriorly directed, conical process. Anal Specimens examined, 176. Ian with 20-24 rays. CHAOBORUS (CHAOBORUS) PUPA BOREALIS NEW SPECIES Total length 8.20-9.50 mm.; respira­ lOl'y horn spindleshaped, somewhat more Comments constricted apically than in C. americanus, This species is very close to the Euro­ finely reticulated on surface, length .86- pean C. crystallinus. The male genitalia .99 mm. Abdominal tcrgite 7 (figure 18E) are quite similar. However, the Nearctic with four pairs of plumose setae posteri­ species has a relatively shorter prementum orly, no lateral setae. Anal paddle (figure and clypeus in both sexes. In the Nearc-

25 tic species the penultimate antenna! seg­ Seta pattern of head essentially as in ment of the male varies from subequal to C. americanus. Color pattern and seta pat­ one and one-half times longer than the ul­ tern in paratypes identical, except speci­ timate, while in C. crystallinus the penul­ mens from Churchill darker grey in ground timate is from one and one-half to two color and have more conspicuous pattern; times longer than the ultimate. specimens from Whitehorse identical with Females of C. borealis have relatively or somewhat paler than type. shorter, narrower wings than C. crystal­ Head width .89 mm.; width between linus. C. borealis also has a distinct spur eyes .44 mm.; length of prementum .24 at the base of RS, while C. crystallinus mm.; length of clypeus .26 mm.; length does not. These differences plus the ex­ of penultimate antenna! segment .24 mm.; treme difference in general habitat indi­ length of ultimate segment .15 mm.; cate that the European and Nearctic forms H.W./W.B.E. = 2.00; H.W./P.L. = 3.64; are distinct and separate species. C. crys­ H.W./C.L. = 3.44; Pu.L.jU.L. = 1.54 tallinus is known from England, Germany, In the paratypes these measurements and Denmark, while C. borealis is known are as follows: head width .87-.91 mm.; only from Churchill, Manitoba; Norman width between eyes .44-.45 mm.; length of Wells, Northwest Territories; and White­ prementum .25 mm.; length of clypeus horse, Yukon Territory, Canada. .24-.27 mm.; length of penultimate anten­ This species is separable from C. flavi­ na! segment .22-.24 mm.; length of ulti­ cans and C. arnericanus by the character­ mate antenna! segment .19-.20 mm.; istics given in the key. It is, in addition, H.W./W.B.E. = 1.96-2.00; H.W./P.L. = distinguished from both by the abdominal 3.38-3.55; H.W./C.L. = 3.36-3.58; Pu.L./ color pattern (figure 14C) and the tho­ U.L. = 1.06-1.21. racic color pattern (figure 13A) in the Thorax (figure 13A) adults. In the males, tergite 9 is not pro­ duced. The larvae are very similar to C. General ground color grey with promi­ flavicans. The most constant difference is nent pattern of dark grey areas (figure the lack of a seta on the anterior face of 13A); paratypes similar except for the the antenna. Churchill specimen, which is darker in ground color and has black markings rather than dark grey; dark areas less Description extensive than in preceding species. MALE Pronotal setae approximately 30; pro­ episternals 8; postpronotals 7; preepi­ Total length 6.00 mm. Paratypes 4.50- stcrnals II; anepisternals 13; upper 6.00 mm. mesepimerals 14; parascutellars 2. In General coloration grey with dark grey the paratypes these counts are pronotals to black markings; setae black on head 35-40 (approximately); proepisternals 7- and on appendages and dorsal region of 10; postpronotals 6; precpistcrnals 6-10; thorax; setae of abdomen grey; setae of anepistcrnals II-12; upper mesepimerals pleural regions light grey; basal one-third 10-14; parascutellars 1-2. of femora with light setae, apically darker; Thoracic appendages apical portions of legs with grey setae. Paratypes identical. Wings clear, slightly infuscated on an­ terior and posterior one-third. Paratypes Head all identical. Wing length 3.25 mm.; width Head capsule light grey, infuscatcd over .81 mm.; W.L.jW.W. = 4.00; W.L./H.W. vertex; frontal stripe and macula dark =3.65. grey; pedicel dark grey; flagellar segments In the paratypcs: wing length 3.18- pale basally, dark grey apically; clypeus 3.25 mm.; width .74-.81 mm.; W.L./W.W. infuscated, lateral margins dark; stipes = 4.19-4.30; W.L./H.W. = s.,H-3.66. Ves­ dark grey; maxillary palpi infuscated; titurc of wings as in preceding species ex­ sclerotized portions of labellae dark grey. cept marginal scales somewhat longer than

26 in C. arnericanus. Length of longer scales mm.; style length .41 mm.; Co.L./St.L. = .164 mm.; shorter scales .071 mm.; para­ 1.31. In the paratypes, coxite length .54- types identical. Wing venation as in C. .57 mm.; style length .35-.40 mm.; Co.L.j americanus except for a short but conspic­ St.L. = 1.36-1.60. uous spur arising at base of RS and di­ rected basad. Vein An terminates .12 mm. FEi\IALE short of m-cu; in paratypes this vein ter­ minates .16-.21 mm. short of m-cu. Total length 4.50-5.50 mm. Females Capitulum of haltere somewhat ovoid somewhat paler than associated males. in type and paratypes; light grey in ground Head color with two patches of darker grey pig­ No setae on frontal maeula; pedicel mentation on inner face surrounding inner bearing four setae; membranous area seta groups; one or two setae anteriorly; around antenna! base pale grey. Head posterior with four setae in type, three to five in paratypes; three irregularly placed width .97 mm.; width between eyes .48 sctae on outer face; pedicel dark grey, mm.; prementum length .27 mm.; elypeus shorter and stouter than C. arnericanus. length .30 mm.; H.W/W.B.E. = 2.02; Legs as in preceding species except setae H.W./P.L. = 3.57; H.W.jC.L. = 3.23. In of outer apical one-third of femora darker female paratypes these measurements are than basal setae. Profemur length 1.72 head width .92-.94 mm.; width between mm.; protibia length 1.85 mm.; first pro­ eyes .45-.47 mm.; prementum length .27- tarsus .92 mm. In the paratypes, profemur .30 mm.; elypeus length .27 mm.; H.W./ length 1.51-1.92 mm.; protibia 1.85-2.03 W.B.E. = 2.00-2.06; H.W.jP.L. = 3.09- mm.; first protarsus .88-.92 mm.; W.L./ 3.57; H.w.;c.L. = 3.42-3.47. Pf.L. = 1.91 in type, 1.65-2.14 in para­ Thorax types. Medial pronotal setae absent; pronotal Abdomen (figure 14C) setae 3.5 (approximately); proepisternals Ground color grey; tergite 1 uniform 7; postpronotals 9; preepisternals 19; anepi­ dark grey; tergites 2-6 with antero-median sternals 13; upper mesepimerals 17; para­ dark patch and paired pale spots outlined seutellars 2. In the paratypes, pronotals with darker pigmentation; setae in areas 24-44; proepisternals 6-10; postpronotals of dark pigmentation surrounded by small 5-10; preepisternals 10-1.5; anepisternals dear spots; sternites of uniform color. Ter­ 14-17; upper mesepimerals 13-19; paraseu­ gitc 7 with a median patch of dark grey. tellars 2. Oenitalia Thoracic appendages Tergite 8 with numerous scattered setae; Vein An somewhat longer than in male, sternite with fewer setae but arranged in attaining level of m-cu in allotype and al least two irregular rows with some scat­ falling .07 mm. short in paratypes. Wing tPred setae anteriorly. Tergite 9 not length 3.8.5 mm.; width 1.14 mm.; W.L./ acutely produced, only a small obtuse pro­ W.W.= 3.35; W.L./H.W. = 3.92. In para­ jection present; lateral setaceous lobes of types these are wing length 3.70-3.77 mm.; lPrgite with 10 long setae, paratypcs with width 1.07 mm.; W.L/W.W. = 3.44-3.51; 9 to 1 I. W.L.;H.W. = 3.77-4.08. Vein m-cu slight­ Gonocoxites uniform dark grey; gono­ ly proximad of r-m, not in line in any style light grey on basal one-fourth, dark specimens examined. grey on apical three-fourths; gonostyle Profemur length 1.62 mm.; protibia with sparse, minute setae on inner surface 1.74 mm.; first protarsus .8.5 mm.; W.L./ hasally and on all surfaces on apical one­ Pf.L. = 2.36. In paratypes, profernur 1.73- fomth. Penis valve (figure 161) trans­ 1.77 mm.; protibia 1.86-1.92 mm.; first pro­ parent, pale, with large spatulate !wad. tarsus .81-.85 mm.; W.L./Pf.L. = 2.12. Head with preapical clawlike spine not ex­ Relative lengths of legs as in C. arneri­ cc'Pding head in length. Coxitc length .5,t camts.

'1.7 Abdomen June 17); 4 oo, 1 '2, Norman Wells, Cerci pale grey. Spermathecae (figure Northwest Territories, June 11-12, 1949, 14M) heavily sclerotized and darkly pig­ W. R. M. Mason. Holotype, allotype, mented; sclerotization on duct as in C. 6 oJ and 4 ¥'2 paratypes in the Canadian arnericanus but ducts more slender and National Collections; 1 o, 1 '2 paratypes shorter, less curved; diameter of sperma­ in the University of Minnesota Collec­ thecae .08 mm., in paratypes .08-.10 mm. tions; 1 d paratype in the U.S. National ::\iuseum. LARVA Specimens also examined: 2 '2'2, White­ Total length 10.00-11.00 mm.; clear, horse, May 18, 1949, L. C. Curtis; 1 '2, nearly transparent, sometimes faintly in­ Churchill, June 29, 1949; 1 '2, Churchill, fuscated dorsally. This larva differs from June 30, 1949; 3 larvae from Churchill. that of C. fiavicans only in the following Total specimens examined, 22. details. Head THE SUBGENUS SCHADONO­ Head length 1.33-1.44 mm.; antenna PHASMA DYAR AND length .55-.62 mm., no seta on anterior face of antenna; antenna! blades .55-.59 SHANNON 111111. long, four in number plus one shorter Schadonophasrna3 Dyar and Shannon, blade .29 111111. long; postantennal filaments 1924, Insecutor Inscitiae Menstruus L?: .55-.59 mm. long, five pairs present; pre­ 212. Type: Corethra trivittata Loew, labral appendages 7.00-7.33 times longer 1862 = C. nyblaei (Zetterstedt), 1838. than broad, two in number, somewhat ser­ This subgenus is monotypic. rate anteriorly, terminating in one long The following differences separate this spine .23-.2-t 111111. long. subgenus as represented by C. nyblaci Mandibular fan with 11-12 setae; man­ from Chaoborus s. str. on the one hand dibles with three major teeth, median and from the species constituting the sub­ tooth with a small basal tooth clearly on genus Sayomyia on the other. Adults of that tooth and not between 2 and 3. C. nyblaei differ from Chaoborus s. str. Thorax and abdomen in the following details: no parascutellar Setae of thorax and abdomen as in C. setac; a prominent spur directed basad at fiavicans; anal fan with 21 to 22 rays. the base of RS; wings spotted; wing veins (aside from marginal scales) obviously PUPA scaled; spermathecae ovoid, with a short Unknown. straight neck; no comblike setal row on third mesothoracic tarsus of females. Specimens Examined C. nyblaei differs from Sayomyia in the Holotype o, Whitehorse, Yukon Territory. presence of well developed pulvilli, in the May 18, 1949, L. C. Curtis. lack of a lobe or paired stout setae on the Allotype '2, Whitehorse, Yitlcon Territory, apical third of the gonocoxite, and in the May 18, 1M9, L. C. Curtis. greater number of thoracic setac. Paratypes, 2 oo, Whitehorse, Yukon Ter­ ritory, May 18, 1949, L. C. Curtis; 1 o, CHAOBORUS (SCHADONO­ Churchill, Manitoba, July 1, 1949; 1 o, Churchill, Manitoba, July, 1949; 2 '2'2, PHASMA) NYBLAEI Churchill, Manitoba, June 23, 1949 (ZETTERSTEDT} (reared from larvae collected June 17, 1949); 2 n, Churchill, Manitoba, July Erioptera nyblaei Zetterstedt, 1838, In­ 1, 1949 (reared from larvae collected secta Lapponica, p. 830.

3 J. Lane (ID53) raises Schadonophasma and Sayomyia to full genera but this seems unjustified on any grounds and is not accepted here.

28 Corethra trivittata Loew, 1862, Berlin Ent. Description Ztschr., Bd. 6, p. 186, [fide Edwards, 1932]. Dyar, 1902, N. Y. Ent. Soc. Jour. MALE 10:201. Johannsen, 1903, N. Y. State Total length 7.50-8.50 mm. Setae pale Mus. Bui. 68, p. 398. Felt, 1904, N. Y. yellowish, or light grey to black. Dark State Mus. Bui. 79, pp. 361-363 (Sayo­ setae usually confined to anterior prono­ myia). Dyar and Shannon, 1924, In­ tum, scutum, scutellum, and legs. General secutor Inscitiae JYienstruus 12:212-213 body coloration varies from light yellow­ (Chaoborus). Edwards, 1930, Nat. Hist. ish-brown to dark brown and from light Mag. and Ann., 10th series 6:533 (Chao­ grey to dark grey. borus). Johannsen, 1934, Cornell Agr. Head Expt. Sta. Mem. 164, p. 44 (Chaoborus}. Head capsule pale in color, darkened Corethra punctipennis, Giles (not Say), over vertex; pedicel dark grey or brown J 902, Handbook of Gnats or Mosqui­ to black; flagellar segments with dark basal toes, 2nd ed., London, p. 502. ring that is pale basad of whorl, dark at whorl, then somewhat paler distad of Sayomyia knabi Dyar, 1905, Ent. Soc. whorl; lateral margins of clypeus, maxillary 4 Wash. Proc. 7:16, footnote 3. stipes, and palpi and sclerotized portion of Chaoborus pallidus, Edwards (not Fabri­ labellae infuscated. cius) in part, 1920, Ent. Monthly Mag. Head width .91-1.17 mm.; width be­ 5U:265. Martini, 1929, in Lindner, Die tween eyes .39-.,53 mm.; length of pre­ Fliegen der Palaearktischen Region, Bd. mentum .37-.50 mm.; length of clypeus 3, Fasc. 11, rn, p. 58. .33-.44 mm.; length of penultimate anten­ na] segment .23-.33 mm.; length of ulti­ Chaoborus nyblaei (Zett.), Edwards, 1930, H.W./W.B.E. ibid., p. 533. Edwards, 1932, Genera In­ mate segment .19-.26 mm.; sectorum, Fasc. 194, p. 26. l\iatheson, = 2.10-2.64; H.W.JP.L. = 2.21-2.72; H.W./ l9t4, Handbook of the Mosquitoes of C.L. = 2.25-2.76; Pu.L.JU.L. = 1.00-1.58. North America, Comstock Pub. Co., Thorax Ithaca, N. Y., p. 94. In fresh specimens thorax light grey in ground color with dark grey or brown to Comments black markings, as in C. americanus. In specimens that have been pinned for 20 The distribution of this species is rather years or more the color has changed to interesting. According to Peus (1934) the yellowish-brown with dark brown mark­ species occurs in the Arctic regions of ings. Pronotal setae approximately 18-37; Europe. In the Nearctic it ranges from proepisternals 4-13; posterior pronotals :\fassachusetts northwards, across northern 4-10; preepisternals 3-8; anepisternals 11- Canada to Alaska, and then south to 18; upper mesepimerals 8-18; paraseutel­ southern California along the coast. In the lars none. In two specimens from Reindeer Sierra Nevada ranges it has been col­ Depot, MacKenzie Delta, N.W.T., these lected as far south as Lake Tahoe, Cali­ counts are: proepisternals 23; postprono­ fornia. has been found in the Canadian It tals 16; preepisternals 9; anepisternals 25; Rockies at Banfl', Alberta and at Kalso, upper mesepimerals 27. British Columbia. The one record for the North Central Thoracic appendages Stales (Wisconsin; Dickenson, 19,14) is Wings (figure 13G) regularly marked erroneous, as the specimen ( examined by with dark grey cloudy spots in membrane; llic author) is a culicine. wing scales and setae light grey except

' Described from a single larva collected at Springfield, Mass. by F. Knab. It is based on the Possession of smooth instead of anteriorly serrate prelabral appendages. The author has what is ap­ parently this specimen (on loan from United States National Museum) bearing the number 96 with a sk(•tch of the smooth appendage on the label and braring the name Sayomyia tridttata with the ''trivittata" scratched out. This is otherwise indistinguishable from the larva of C. nyblaei. 29 dark over wing spots and white on Costa Head and subcosta for a short distance near Antenna] pedicel bearing 5-15 setae. apex of subcosta and on Costa between Width .91-1.25 mm.; width between eyes apex of Sc and R 1. Wing length 3.70-5.00 .27-.44 mm.; prementum length .31-.48 mm.; wing width .92-1.22 mm.; W.L./ mm.; clypeus length .32-.45 mm.; penulti­ W.W.= 3.81-4.25; W.L./H.W. = 3.92-4.37. mate antenna] segment length .14-.19 mm.; Lanceolate scales of posterior margin from ultimate segment length .15-.22 mm.; .21-.23 mm. in length for the longer and H.W.jW.B.E. = 2.66-3.45; H.W./P.L. = .07-.10 for the shorter (measured at apex 2.40-3.27; H.W.jC.L. = 2.40-3.00; Pu.L./ of An). Vein An ends from .21 mm. short U.L. = .70-1.22. of level of m-cu to directly opposite m-cu. Thorax Capitulum of haltere near spherical; Chaetotaxy nearly identical with that color white to pale grey; two to three of male except usually from three to seven setae on outer face and two to four setae median pronotal setae. on inner face, both in vertical, somewhat irregular rows. Thoracic appendages Legs pale grey in ground color; femur Wing length 3.77-5.59 mm.; wing width with dark ring apically; tibia with dark 1.14-1.70 mm.; W.L.jW.W. = 3.20-3.71; rings both apically and basally; tarsus 1 W.L.jH.W. = 3.88-4.83. Vein An termi­ dark apically and basally; remaining tarsi nates from level of m-cu to .33 mm. be­ uniformly slightly infuscated. Setae of yond level of m-cu. femora long, rather sparse; setae of tibiae Length of profemur 1.77-2.59 mm.; pro­ of equivalent length, more numerous; setae tibia 1.88-2.85 mm.; first protarsus .92-1.33 of tarsi short (one-half the length of those mm.; W.L.fPJ.L. = 1.91-2.93. on femora) , very dense. Profemur 1 .8.5- Abdornen 2.74 mm.; protibia 1.88-2.88 mm.; first Ground color light grey; pattern of dark protarsus .81-1.37 mm.; W.L./Pf.L. = markings more variable than in males, 1.72-2.15. ranging from mere dark spots around seta Abdornen (figure 14D) bases on tergites 1-8 to dark medial bands Ground color light grey; segments 2-7 on tergites 2-7; sternites scarcely marked, with medial, dark, broad ring; tergite 1 some with medial dark band. Paired pale dark on anterior two-thirds; sternite 1 not spots on tergites 2-6. developed. Segment 8 somewhat darkened, Genitalia (figure 15A) uniform; paired pale spots on tergitcs 2-6 Sternite 8 with postero-median dark present but inconspicuous. patch cleft by a narrow longitudinal pale Genitalia line. Cerci light grey. Spermathecae (figure Tergite 8 with numerous scattered setae; 14J) heavily sclerotized and pigmented; sternite with a double or triple transverse pigmented part of ducts short and slighlly row of setac. Tergite 9 apically produced, curved. Diameter of spermathecae .07-.09 rounded; basal lobes of 9 with 9-12 long mm. setae. Gonocoxites dark grey to nearly LARVA black. Gonostyles three-fourths as long as coxites, dark grey to black, bearing sparse, Total length (last instar) 15.00-19.00 minute setae. Penis valve (figure 16J) mm. Colorless, clear, nearly transparent. light to dark grey; head large with large, Canadian specimens infuscated dorsaJly. preapical clawlike spine extending well The pigmentation that is present is as in beyond apex of head. the larvae of C. arnericanus. llead FEMALE Head length 1.50-2.78 mm.; antennae Total length 5.00-7.00 mm. Color pat­ (figure l 7J) .70-1.18 mm.; no setae on an­ tern as in males, except somewhat paler terior face. Antenna] blades .51-.70 mm .. and abdomen less conspicuously ringed. four in number, plus one shorter blade 30 .27-.48 mm. long. Postantennal filaments ford (larvae, Feb. 8, and adults) , Oak­ .57-.96 mm.; prelabral appendages (figure land, Mendocino County, Humboldt 17B) 4.5 times longer than wide, similar County, Lake Tahoe, San Luis Obispo in outline to those in C. flavicans, irregu­ County, Green Valley (Solano County) larly long-serrate on apical one-half of an­ (adults, larvae, pupae), Yosemite; May terior face, smooth posteriorly, terminating 4-Oct. 17. M. anitoba: Gillam, Churchill; in one to three long apical spines .34-.35 July 17-July 30. Massachusetts: Spring­ mm. in length. In Canadian specimens field (larvae and adults) , Amherst; April these appendages are broader and more 28-Oct. 7. New York: June 13. Northwest deeply serrate, three times longer than Territories: Reindeer Depot (MacKenzie broad. Delta), Yellow Knife; Aug. 13-Aug. 1'7. Labrum with two pairs of small setae Nova Scotia: February. Ontario: Belle­ on anterior face; anterior face of labral ville (larvae). Oregon: Portland, Philo­ apex imbricated with stout, bifurcate, flat­ math (larvae and adults); May 27. Que­ tened setae plus two pairs of laterally lo­ bec: Great Whale River; Aug. 13. Yukon cated seta clusters or fans; each labral Territory: Whitehorse; May 14-August 1. fan with 12-15 setae each, no pectinate Specimens examined, 121. setae. Mandibular fan with 13-20 setae, none pectinate; mandible (figure 17G) ,,·ith three major teeth, median tooth larg­ THE SUBGENUS SAYOMYIA est with a small basally attached tooth COQUILLETT not attaining level of posteriormost at apex; posterior tooth with five small teeth Sayomyia Coquillett, 1903, Canad. Ent. on posterior margin at base. 35:189-190. Type: Corethra punctipen­ Thorax and abdomen nis Say. Abdominal segment 9 with a short, This name was originally proposed by stout, conical process on dorsum; anal fan Coquillett as a generic name. He believed with 24-33 long, short-plumose rays. Anal M ochlonyx Loew to be a synonym of apparatus much as in C. americanus ex­ Corethra Meigen and that Corethra should cept pectinate processes more prominent. be assigned to specimens previously called M ochlonyx. This left the species to which PUPA Corethra had previously been assigned Total length 8.00-10.00 mm. Cephalo­ without a name, and Coquillett proposed thorax one-fourth total length. Colorless Sayomyia. The discovery of the earlier except as adult pigmentation appears. Res­ name Chaoborus Lichtenstein sank Sayo­ piratory horns spindleshaped, finely re­ myia as a synonym until its resurrection ticulated on surface; length 1.02-1.13 mm. by Dyar and Shannon (1924) as a sub­ Abdominal tergite 7 (figure 18G) with generic name. three pairs of plumose setae posteriorly Edwards (1932) characterizes this sub­ and one pair laterally. Anal paddle (figure genus as follows, "Pulvilli absent (except ISF) not distinguishable from that of in some neotropical species). Venation: C. flavicans. Inner rib serrate for distal Rs usually shorter than in Chaoborus s. three-fourths; lateral rib smooth exter­ str., angled at base, with a shorter or nally; median rib well developed with a longer spur extending from the angle to­ plumose seta at middle and a minute seta ward the base of the wing. Extreme tip at distal end. of Cu2 faint or absent; a hairy spur ex­ tending forward from near the tip of Cu2 parallel with wing margin, usually long Specimens Examined and sometimes reaching the tip of Cu1. Alberta: Banff; July 21. Baffin Island: An reaching only slightly beyond the base Lake Harbor; Aug. 7. British Columbia: of cubital fork. Wing fringe usually long. Kalso, Canim Lake, Trinity Valley, Vic­ Wings with or without markings. Pupal toria; June 13-Oct. 4. California: Stan- respiratory horns sometimes more swollen 31 than in typical Chaoborus, even almost Comments globular." The description of this species that fol­ To Edwards' diagnosis may be added a lows will indicate that there is a consider­ few more characteristics and a few restric­ able amount of variation in color and in tions for the Nearctic species. Known Ne­ absolute and relative size. Examination of arctic species all with wing markings; pul­ a few specimens from widely separated villi not absent but minute, setaceous; areas (northern 1\1:innesota and southern parascutellar setae absent, mcsepimeral Louisiana) would suggest that at least two setae eight or fewer, preepisternals four distinct species arc involved. or fewer; no paired, pale patches on ab­ However, as additional specimens are dominal tergites 2-6; gonocoxite of male examined, a continuous variation in size with a lobe on inner face bearing two stout and proportions is revealed with no dis­ setae or at least with paired stout setae tinct discontinuities. In addition, while (C. albatus); third segment of mesotho­ size is in general smaller in the southern racic tarsus of female with double row of specimens, there is no absolute correla­ short setae extending over apical two­ tion with geographical distribution. Very thirds of posterior surface, forming an open small specimens are found in Iowa while comb similar to that in C. americanus; larger forms are found in southern Illinois females without setae on frontal macula some 400 miles further south. and without median pronotal setae; me­ Also, the smallest specimen that the au­ dian mandibular tooth of larvae without a thor has seen was collected at Mound, basally attached tooth; larval labrum with Louisiana, while a few miles south at a pair of stout setae located medially on Natchez, Mississippi, several specimens anterior face; abdominal segment 9 with a were collected which are only slightly conical dorsal process appearing two­ smaller than the average size of all of segmented. the l\Iinnesota specimens examined. The color variation is nonsignificant, since all CHAOBORUS (SAYOMYIA) gradations of color available throughout PUNCTIPENNIS (SAY) the range are to be found in collections from single localities in Minnesota. Corethra punctipennis Say, 1823, Acad. In regard to the larvae, there arc con­ Nat. Sci. Phila. Jour. 3:16. Johannsen, siderable size differences between those 1903, N. Y. State Mus. Bul. 68, p. 397. collected from small bodies of water and Felt, 1904, N. Y. State Mus. Bul. 79, those from larger lakes. :Mature larvae p. 361 (Sayomyia). Knab, 1908, Ent. from Iowa, which were collected in a small Soc. Wash. Proc. 10:36-40, figs. 5-8. pool in September, are all approximately Dyar and Shannon, 1924, Insecutor In­ the same size and constitute the minimum scitiae Menstruus 12:213 (Chaoborus). sizes in the measurement ranges given. Al Matheson, 1925, Canad. Ent. 57:159- the same time larvae collected in Decem­ 160. Edwards, 1932, Genera Insectorum, ber in Lake Mendota, Wisconsin show :Fasc. 194. Johannsen, 1934, Cornell Agr. little size variation and constitute the Expt. Sta. Mem. 164, p. 43, pl. 18, fig. maximum sizes in the range given. Larvae 165. Lane, 1942, Rev. de Ent. 13:140- from other areas and other times are in­ 141. Matheson, 1944, A Handbook of termediate. Muttkowski (1918) indicates the l\fosquitocs of North America, Com­ that the summer broods of larvae are al­ stock Pub. Co., Ithaca, N. Y., p. 94, ways smaller at maturity than the over­ pl. 10, fig. 1. Lane, 1953, Neotropical wintering larvae in Lake l\fondota. Culicidae, Sao Paulo, Brazil. This species is found throughout the Corethra appendiculata Herrick, 1884, eastern part of North America from Flor­ Geological and Natural History Survey ida to southern Ontario and west to cen­ of Minnesota, 12th Annual Report for tral Saskatchewan, Colorado, and central 1883, pp. 10-11, pl. V (not 5), figs. 1-4. Texas. It has been recorded by J. Lane New Synonomy. (l 942) from Jalisco, Mexico. The larvae are found in large lakes, eated in figure; setae at these points red­ in small ponds, and, according to Knab brown; length 1.70-2.80 mm.; width .48-.74 (1909), in nvers. mm.; W.L./W.W. = 3.33-3.88; W.L./H.W. = 2.78-3.71. Longer lanceolate scales of Description posterior margin from .143-.171 mm.; the

MALE shorter from .057-.073 mm. M 2 sharply angled at base; An terminates proximad Total length 3.30-5.50 mm. Antenna! of level of m-eu; r-m slightly distad of setae yellowish; thoracic and abdominal m-eu. setae yellowish-brown; setae of legs yel­ lowish-brown except dark brown at tarsal Capitulum white to very pale grey, apices. General body coloration pale grey somewhat ovoid, bearing one or two setae to yellowish with more or less numerous on outer face and two or three setae on red-brown spots on abdomen and on fe­ inner face. mora and tibiae. Legs marked with reddish-brown spots. Femora and tibiae variously spotted ex­ Ilead cept at ends with larger or smaller mark­ Head capsule light yellowish or cream ings, some forming almost complete rings, colored, slightly darkened over vertex; most nearly ringlike on profemora. In pedicel red-brown; flagellar segments pale addition, profemur and protibia with with a red-brown ring at setal whorl; pro­ broad distal ring; mesofemur and meso­ boscis (including clypeus and prementum) tibia with but faintly marked distal light reddish-brown; palpi brown, except segment 2 pale on basal one-half. Only ring; metafemur and metatibia with a single row of setae on either side of rather broad, conspicuous apical ring; Iron ta! stripe. each tarsal joint except last with con­ Head width .51-.75 mm.; width between spicuous apical ring. Profemur 1.00- eyes .18-.2'2 mm.; length of prementum 1.3:J mm.; protibia .92-1.41 mm.; first .17-.24 mm.; length of clypeus .H-.21 mm.; protarsus .48-.70 mm.; W.L.jPf.L. = 1.71- length of penultimate antenna! segment 1.91. Claws yellowish, darker at tip. .15-.22 mm.; length of ultimate antenna! Jbclomen (fig11re 14E) segment .12-.21 mm.; H.W./W.B.E. =2.77- Ground color of abdomen pale grey; 1.10; H.W./P.L. = 2.93-3.33; H.W./C.L. = tergites 1-G \Yith latero-median area red­ :l.27-3.91; Pu.L./U.L. = 1.00-1.25. dish-brown, seta bases in dark red-brown 'f'horax spols. Stcrnites with antero-lateral areas Thorax pale grey in ground color with reddish-brown and all seta bases in dark red-brown darkened areas (figure 13B). red-brown spots; sternite I not developed. .\ntcrior pronotal lobes darkened medi­ Segment 7 with both tergite and sternite ally; posterior pronotum darkened at up­ darker than preceding segments. per margin; vittae of scutum reddish­ Genitalia (figmes 16A, 16B) brown; sctac of scutum arise from small Tergite and sternite 8 with numerous reddish-brown spots or pinnaculae; scutel­ long setae on posterior half. Tergite 9 pro­ lnm, postnotum, anterior margin of an­ duced apically into a broadly rounded lobe terior ancpisternum, lower two-thirds of with a pair of but slightly differentiated prcepislcrnum, pleural apophyseal area, basal lobes: rnch basal lobe with 11-20 long and epimcron all reddish-brown. Pronotal selae. Gonocoxiles (figure 16A) sordid .selae approximately 18-35; proepisternals white to very pale gray on basal two­ (i-9; posterior pronotals 2-3; preepisternals thirds, reddish-brown on apical third. 0-2: anepislernals 9-1-t; upper mesepimerals Gonocoxites with lobe on dorsal surface. :l-G. This lobe bears numerous small, rather fine Thoracic appendages setae and, in addition, two stout setae Wings (figure 13D) translucent, milky, directed antero-mesally. Gonostyle approx­ marked with reddish-brown spots, as indi- imately one-third shorter than gonocoxite,

33 pale basally, red-brown on apical third, LARVA bearing a few minute setae along its length. Total length 7.50-9.50 mm. (Eggleton, Penis valve (figure 16B) pale basally, red­ 1932, states that they attain a length of brown to dark brown apically. Apex en­ ll.(i5 mm.); clear, practically transparent; larged and circular with small preapical eyes dark purple; mandibular teeth, an­ spine. Coxite length .28-.44 mm.; gono­ tenna! blades, and postantennal filaments style length .20-.27 mm.; Co.L./St.L. = l.43-l.7G. yellowish; tracheal sacs with black pigment cells; thoracic and abdominal setae color­ FEMALE less, transparent. Head length .85-1.11 mm.; antennae Total length 2.60-4.00 mm. Color and (figure 17M) .35-.50 mm., one small seta color pattern essentially as in male; darker (.021-.026 mm. long) on anterior face at a areas somewhat more extensive; somewhat point .4 antenna! length from base; longer darker than associated males. antenna! blades .32-.50 mm. long; shorter Head blade .24-.32 mm. long; postantennal fila­ Pedicel bearing three to six setae. Head ments .38-.48 mm. long; prelabral append­ width .48-.75 mm.; width between eyes ages (figure 17C) 16-20 times longer than .12-.24 mm.; prementum length .17-.28 wide, irregularly long-rayed for full length mm.; clypeus length .14-.24 mm.; H.W.j anteriorly and for apical three-fourths W.B.E. = 3.14-3.78; H.W./P.L. = 2.47- posteriorly; these appendages .22-.31 mm. 3.42; H.W.jC.L. = 2.76-3.40. long. Head capsule with five pairs of plumose Thorax setae, three dorsal, one subocular, and one Pigmented areas of thorax more ex­ postocellar; labrum with two pairs of setae tensive than in male. Pronotal setae 12-30; on anterior face, proximal pair quite mi­ proepisternals 4-7; postpronotals 2-6; pre­ nute, distal pair quite obvious (similar to episternals 1-4; anepisternals 9-22; upper C. astictopus, figure 17P), .065-.114 mm. mesepimerals 2-8. long; anterior face of labral apex imbri­ Thoracic appendages cated with small bifurcate setae and two Wing length 1.51-2.96 mm.; width .55- lateral pairs of setal fans, the most distal .96 mm.; W.L./W.W. = 2.70-2.97; W.L./ pair of approximately 15 setae each, inner­ H.W. = 2.70-3.95. Scales of wings gener­ most four pectinate medially; most proxi­ ally pale and slender; those arising from mal pair of approximately seven setae pigment spots, unlike those of males, both each; small clusters of minute spines on head anterior to mandibles and on attenu­ dark in color and broader. Vein Cu2 sharply angled at distal end, attaining ated anterior portion behind antennae. wing margin, with spur running parallel Mandibular fan with 12-27 setae. Man­ dibles (figure l 7F) with three major teeth, to margin toward Cu1. Legs slightly longer than in males; pro­ posterior tooth with three small teeth on femur length .88-1.40 mm.; protibia length posterior margin; mandibular teeth pre­ .88-1.59 mm.; first protarsus length .40- ceded by two long setae, one short seta, .74 mm.; W.L./Pf.L. = 1.83-2.29. and two small spines . Setae of thorax and abdomen largely Abdomen and genitalia (figure 15B) plumose, transparent. Anal fan with 16-22 Abdominal color pattern as in male ex­ rays. cept dark pigmentation more extensive. PUPA (figures 18H, 181) Cerci pale yellowish or very light grey; spermathecae (figure 14K) ovate, heavily Total length 7.00-9.00 mm. Cephalo­ sclerotized, dark brown; neck of duct thorax one-quarter of length; colorless, sclerotized, pigmented, short, conical; di­ transparent as in larva. Respiratory horn ameter of spermathecae .050-.057 mm. spindleshaped, coarsely reticulated; length

34 .60-.68 mm. Abdominal tergite 7 with three CHAOBORUS (SAYOMYIA) pairs of plurnose setae. Anal paddle with mesa] rib closely serrate for distal three­ ASTICTOPUS DYAR AND fourths; lateral rib with one to three small SHANNON teeth at distal end; median rib weakly de­ Chaoborus astictovus Dyar and Shannon, veloped, incomplete, bearing a plurnose l 024, Insecutor Inscitiae J\,lenstruus 12: seta and a minute, simple seta just proxi­ 214. Edwards, 1932, Genera Insectorurn, rnad of middle. Fasc. 19-1, p. 26. Deonier, 1943, Ent. Soc. Arner. Ann. 36:383-388. Type lo­ Specimens Examined cality: East Lake, Tulare County, Calif.5 Alabama: Flatwood; June 10. Colorado: Chaoborus lacustris Freeborn, 1926, Pan­ Ft. Collins; Aug. 5-Sept. 16. Connecticut­ Pacific Ent. 2:161-163. Edwards, 1932, Rhode Island: Killingly Pond; Aug. 19. ibid., p. 26. Herms, 1937, Calif. Agr. Florida: Miami; Dec. 9. Georgia: Okefeno­ Expt. Sta. Bul. 607, pp. 1-22. kee Swamp, Spring Creek; June, July. Illinois: Springfield, Dubois, Urbana, Ha­ Comments vana, East St. Louis, Olive Branch, Sa­ The author has examined a topotype c! vanna (larvae and adults) , Danville (lar­ of this species collected in the same series vae, November); April 2-1-Sept. 5. Indi­ by the same collector as the type and a c! ana: Cedar Lake; July 17. Iowa: Ames, paratypc of C. lacustris. These are con­ Lacy-Kocsauqua State Park, Backbone specific. State Park (larvae and adults); July 4- The species is most closely related to Sept. 10. Louisiana: Mound; July 21. C. punctivennis. Aside from the difference 1vlaryland: Plurnrners Island, Forest Glen; in range occupied (C. astictovus is con­ May 5-Aug. 20. Massachusetts: Melrose, fined to the Pacific Coast) , definitive dif­ Wilmington; ,June. Michigan: Washtenaw ~er:nces are difficult to find. C. astictopus County, Douglas Lake, Grand Junction; 1s m general more pale. The fernora and July. Minnesota: McGregor, Lake Lida, tibiae are marked with smaller brown Itasca State Park, Cass Lake, St. Paul, spots, each of which surrounds a single Whitefish Lake, St. Louis County, Olm­ seta, while in C. punctipennis these spots sted County, Crookston, Chisago County, are larger and usually surround several Little Falls, Fergus Falls; June 16-Sept. setac. In addition, there are no spots :?5. Mississivpi: Natchez, Bayou St. Louis; around the setae on the rnesonoturn or the :\fay 16-June 17. Missouri: Parkville, St. abdomen in C. astictopus, while spots are Louis; May 25-29. New Yark: McLean present in both areas in C. punctipennis. Reservoir, Long Lake, Old Forage, Ithaca The larvae are practically indistinguish­ (larvae); July 13-Aug. 13. Ontario: Brule able except on the basis of a single seta Lake, Lake of Bays, Ottawa, Orillia; on the anterior face of the antenna. In ,June 23-Aug. 22. Quebec: Kingsrnere, C. vunctipennis this seta is quite short, Lanie], Aylmer, Knowlton, Norway Bay; .021-.026 mm. in length, while in C. astic­ June 28-Scpt. 7. Saskatchewan: vVaskesiu; topus this seta is somewhat larger, .034 .\ug. 8. Tennessee: Sugartree; July. Texas: mm. long . Brownsville, Richmond, Zavella County, The species is found from Portland, San Antonio, Ft. Worth (larvae), Har­ Oregon to southern California, in moun­ lingen; l\Iar. 15-Aug. 26. Virginia: Grassy­ tainous areas as well as at lower elevations. mcadc, Richmond; Feb. 3-Aug. 31. lVash­ Description inyton, D. C.: Aug. 21. Wisconsin: Schulls­ hcrg, Madison (larvae and adults); May MALE ~6-Aug. 28 (larvae in December). Total length 3.00-5.00 mm. All setae Speeimens examined, 501. pale yellowish to golden yellow. General

6 This type locality has been determined by Dr. Alan Stone. g;; body coloration white to pale grey. Fem­ on outer face and two or three setae on ora and tibiae with numerous small (some­ anterior part of inner face. times obscure) reddish-brown spots. Tho­ Femora and tibiae pale grey to white, rax and abdomen with patterns of dark with numerous small brown spots, each brown to reddish-brown markings. surrounding the base of a single seta; these Head spots restricted to outer face of profemora, Head capsule pale grey or white, pale protibiae, mesofemora, mesotibiae, and an­ terior face of metafemora and metatibiae. brown over vertex; pedicel brown; flagellar segments pale, a narrow brown ring at base All femora with brown distal rings; all tibiae with both proximal and distal rings; of each setal whorl; proboscis pale brown; maxillary palpi grey-brown with grey se­ first and second tarsal segments darkened distally. tae, segment 2 white on basal one-half. i\fetathoracic leg longest, approximately Head width .57-.64 mm.; width between 5.00 mm. from coxa to claw; prothoracic eyes .20-.24 mm.; length of prementum leg .83 as long as metathoracic; mesotho­ .!W-.2.\l mm.; length of clypeus .17-.18 mm.; racic leg .68 as long. Profemur 1.14-1.40 length of penultimate antenna! segment mm.; protibia 1.18-1.40 mm.; first protar­ .15-.16 mm.; length of ultimate antenna! sus .55-. 70 mm. segment .12 mm.; H.W./W.B.E. = 2.53- 2.85; H.W./P.L. = 2.69-2.85; H.W./C.L. = Abdornen (figure 14F) 3.30-3.46; Pu.L/U.L. = 1.22-1.28. Ground color pale grey or white. Ter­ gites 1-6 with paired brown areas extend­ Thorax ing almost full length of lateral margins Thorax pale grey to white or cream­ and projecting mesally as dark brown white in ground color with brown to red­ triangles. Tergites 7 and 8 wholly dark­ dish-brown markings; anterior pronotal ened. Sternite 1 not developed; sternites lobes darkened antero-medially or antero­ 2-6 with smaller paired brown patches dorsally; posterior pronotum darkened at located laterally; sternites 7 and 8 almost upper angle; vittae of scutum brown and entirely dark. may or may not be margined with darker brown; in addition, scutum may or may Genitalia ( figures 16E, 16F) not have a brown mark on either side of Tergite and sternite of segment 8 with median vittae anterior to lateral vittae; no numerous long setae medially on tergite, spots around seta bases; scutellum dark­ confined to posterior margin on sternite. ened at sides; postnotum, anterior anepi­ Tergite 9 produced into a slight median sternum, area of pleural suture and pleural lobe; a pair of slightly differentiated lateral apophyseal pit, epimcron, and lower two­ lobes on either side on posterior margin, thirds of preepisternum all red-brown. each bearing 12-14 long setae. Gonocoxites Pronotal setae 12-21; proepisternals 6-7; white to pale grey on anterior two-thirds, postpronotals 2-4; preepisternals 1-2; anep­ brown on apical third; gonocoxites with isternals 8-10; upper mesepimerals 3-4. small lobe on inner, dorsal surface. This Thoracic appendages lobe bears two stout setae and a few short Wings (figure 13E) translucent, milky, fine setae. Gonostyle one-fourth to one­ marked with brown spots as in illustration. third shorter than gonocoxite, pale basally, Scales rising from these darkened spots dark brown on apical half, bearing few brown; the remaining scales pale. ,ving minute setae along its length. Penis valve length 2.03-\l.66 mm.; width .57-.70 mm.; (figure I6F) pale basally, dark brown api­ W.L. /W.W.=-= 3.57-3.79; W.L. /H. W. = cally, apex bifurcate with two short blunt 3.57-4.35. Lanceolate scales of posterior processes. Coxite length .28-.40 mm.; style margin of two alternating lengths, the length .21-.27 mm.; Co.L.jSt.L. = 1.33- 1.52. longer .145-.158 mm., the shorter .057- .065 mm. FEMALE Haltere pale grey to white; capitulum Total length 2.50-4.00 mm. Coloration somewhat ovoid, bearing one or two setae and color pattern essentially as in males.

36 Head anterior face and on apical half of poster­ Pedicel bearing two to five setae. Head ior face. Labrum (figure 17P) with two width .55-.65 mm.; width between eyes pairs of setae on anterior face, proximal .17-.21 mm.; prementum length .20-.24 pair quite minute, distal pair quite obvi­ mm.; clypeus length .17-.20 mm.; H.W./ ous, .11-.14 mm. long. A small cluster of W.B.E. =2.86-3.33; H.W./P.L. = 2.35- spines on head capsule just anterior to base 2.70; H.W.jC.L. = 2.88-3.33. of mandibles. Mandibular fan with 13-22 blades (Deonier, 1943, cites one example Thorax in which a specimen had 15 blades on one Pronotal setae 10-25; proepisternals 5-7; mandible and 22 on the other). postpronotals 1-3; preepisternals 1-2; an­ episternals 10-17; upper mesepimerals 3-7. Thorax and abdomen Setae of thorax and abdomen largely Thoracic appendages plumose, colorless. Abdominal segment 9 Wing length 2.07-2.77 mm.; wing width with an elongate, tapering, dorsal process .66-.92 mm.; W.L./W.W. = 2.83-3.10; that appears to be two-segmented (figure W.L/H.W. = 3.50-4.40. Scales of wings 18J); anal fan with 15-19 rays. generally pale and slender except those arising from pigmented areas broader and PUPA dark brown. Vein Cu2 sharply angled at Southern California specimens only distal end, attaining wing margin, some­ Total length 4.8-6.2 mm. Cephalothorax times with a spur running parallel to wing two-sevenths of total length; colorless, margin toward Cu . 1 transparent as in larvae (opaque white in Legs slightly longer than in males. Pro­ alcoholic specimens) . Respiratory horn femur length 1.07-1.33 mm.; protibia 1.18- spindleshaped, rather more rotund than 1.40 mm.; first protarsus .55-.62 mm.; in C. punctipennis; coarsely reticulated; W.L/Pf.L. 1.90-2.24. = .57-.82 mm. long. Abdominal tergite 7 with Abdomen three pairs of plumosc setae as in C. punc­ Cerci pale grey or white, covered with tipennis. Anal paddle (figure 18K) with short yellowish setae; spermathecae (figure mesa! rib very sparsely serrate medially, 14L) ovate to spherical, heavily sclerotized only one or two irregular serrations on and pigmented; neck of duct short, conical, apical third; lateral rib with one, two, or more obvious than in C. punctipennis; di­ no teeth at apex; median rib weakly devel­ ameter of spermathecae .078-.085 mm. oped but complete, bearing a plumose and a minute, simple seta just proximad of LARVA midline. Total length 8.00-10.50 mm.; clear, prac­ Specimens Examined tically transparent; eyes black; mandibular teeth and setae, antenna! blades and post­ Paratype J of C. lacustris Freeborn. antennal filaments, and margin of fora­ California: East Lake (topotype), Lake­ men magnum all pale yellow; anal fan and port. Woodlake, Clear Lake, Nice, Hop­ anal apparatus pale yellow; tracheal sacs land, Upper Lake, :'.\fiddlctmrn, Potter with black pigment cells dorsally; plumose Valley, Lassen County, Palo Alto, Morgan setae of head, thorax, and abdomen clear Hill, Stanford (larvae), Sanger, Loma and transparent, colorless. Head length .80- Linda, Exeter, Lake Sherwood (Ventura 1.11 mm.; antennae (figure 17N) .32-.54 County) (adults, larvae, pupae), Irvim• mm.; a small seta (.034 mm.) on anterior Lake (Orange County), Agoura (Los face .3 antenna! length from base; longer Angeles County), Malibu Lake, Chats­ antenna! blades .35-.45 mm., shorter blade worth (Los Angeles County): April 22- .'/5-.31 mm.; postantennal filaments .37-.46 Oct. 1 I. Oregon: Portland, Harrisburg (lar­ nun. long; prelabral appendages (figure vae) , Siltcoos Lake (larvae) ; May 17- 17D) .21-.30 mm. long, 17 to 21 times J uly 15. longer than wide, irregularly long-rayed on Specimens examined, 267.

37 CHAOBORUS (SAYOMYIA) a brown band extends across lower part of proepimeron and anepisternum; preepi­ ALBATUS JOHNSON sternum either with lower two-thirds Chaoborus albatus Johnson, 1921, Boston brown or with a narrow band of brown Soc. Nat. Hist. Occas. Papers 5:11. Dyar extending horizontally across preepister­ and Shannon, 1924, Insecutor Inscitiae num in a line one-third of distance from J\Ienstruus L?:2B. Edwards, 1932, Gen­ top. Pronotal setae 17-23; proepisternals era Inscctorum, Fasc. 194, p. 26. J\'Iathe­ 8-10; posterior pronotals 2-3; preepister­ son, 19±4, A Handbook of the Mosqui­ nals 1-2; anepistcrnals 13-14; upper mesepi­ toes of North America, Comstock Pub. merals 3-5. Co., Ithaca, N. Y., p. 94. Thoracic appendages Description Wings (figure 13F) translucent, milky, marked with brown spots as illustrated; :VIALE length 2.03-2.70 mm.; width .59-.72 mm.; Total length 4.00-5.50 mm. Antenna! W.L./W.W. = 3.43-3.72; W.L./H.W. = setae pale cream or white; thoracic and 3.43-4.10. The longer lanceolate scales of abdominal sctae white; sctac of legs white posterior margin .157-.171 mm.; the shorter except at brown rings where setae are .057-.073 mm. greyish or pale brown. General body color­ Legs without spots; femur with brown ation white or pale cream; a few brown ring just before distal end; tibia with markings on thorax and abdomen; no spots brown ring just beyond proximal end and on legs. a brown ring at distal end; tarsal seg­ Head ments 1-4 with distal ends brown, tarsus 5 pale. Profemur 1.11-1.44 mm.; protibia Head capsule white or pale cream, light 1.22-1.55 mm.; first protarsus .22-.27 mm. brown over vertex; pedicel light brown; Claws brown. f!agellar segments white, a thin brown ring at base of each setal whorl; proboscis very Abdomen (figure 140) light brown; setac of head somewhat more Ground color white to very pale cream; numerous than in C. punctipennis. Palpal antero-lateral corner of tcrgites 2-8 brown segments all pale brown except segment (8 sometimes pale); sternites 3-6 similarly 2 white on basal two-thirds. marked. Head width .60-.65 mm.; width between Genitalia (figures lliC, IUD) eyes .15-.l 8 mm.; length of prementum .17-.24 mm.; length of clypeus .17-.18 mm.; Tergitc and sternite of segment 8 with length of penultimate antenna] segment numerous long setae on posterior half. Ter­ .26-.28 mm.; length of ultimate segment gite 9 not produced; a pair of slightly de­ .16-.19 mm.; H.W./W.B.E. = 3.23-1.17; veloped basal lobes on either side posteri­ H.\V.jP.L. = 2.70-3.33; H.W./C.L. = 3.30- orly, each bearing 13-15 long setae. Gono­ 3.53; Pu.L./U.L. = 1.36-1.65. coxite white on basal two-thirds, brown on distal one-third. Gonocoxite without lobe. Thorax Gonostyle from one-fourth to one-third Thorax white to vcry pale cream, with shorter than gonocoxite, pale brown. brown markings (figure 13C). Anterior sparsely beset with minute setae. Penis pronotal lobes wholly white or brown only valve (figure l GD) with apex brmrn. on lower half of anterior portion; posterior otherwise pale; valve simple, clawlike. pronotum with or without a small brown without hifnrcation of apex or preapical patch at upper angle; scutum with brown spmc. Coxite length .30-A0 mm.; style vittae and a pair of small brown patches length .22-.27 mm.; Co.L./St.L. = Ul­ on either side of medial pair of vittac and l.47. anterior to lateral pair; no marks around scta bases; scutellum white or pale cream; FE:VIALE postnotum brown; dorsad of pleural cleft Total length 3.50-4.00 mm.

38 Head slightly less than seven times longer than Pedicel bearing five to seven setae. Head wide, resembling those of C. fiavicans, .20 width .62-.68 mm.; width between eyes mm. long, serrate anteriorly on distal .21-.24 mm.; prementum length .21-.27 three-fourths and posteriorly on distal half . mm.; clypcus length .20-.24 mm.; H.W.j Labrum with two pairs of setae on an­ W.B.E. = 2.7 5-2.93; H.W./P.L. = 2.42- terior face, the proximal minute, the distal 2.93; H.W./C.L. = 2.82-3.14. pair quite obvious (.066 mm. long). Apex of labrum armed as in C. punctipennis. Thorax Mandibular fan with nine setae. Mandibles Pronotal setae 20-31; proepisternals with three major teeth, posterior tooth 7-10; posterior pronotals 2-3; preepisternals with four small teeth or spines on posterior 1-4; anepisternals l:l-21; upper mesepi­ margin. Anal fan with 17 setae. mcrals ,5-7. Thoracic appendages Specimens Examined 'Wing identical with that of male, ex­ Illinois: Peoria; June 15. Indiana: Cedar cept at distal ends of veins R4 + 5 , Cu1, and Lake; July 17. Louisiana: Kilbourne; May Cu2 there may be brown pigment patches. IO. 111assachusetts: Brookline; June 28. Wing length 2.51-2.81 mm.; wing width ivlichigan: Roscommon County; July 14 . . 77-.96 mm.; W.L.;W.\V. = 2.80-3.24: },Jinnesota: Fergus Falls, Olmsted County, W.L./H.W. = :l.89--Ul. Profemur length Bemidji, Cass Lake, Gull Lake; June 14- l.IS-1.33 mm.; protibia length 1.33-1.48 Aug. 17. New York: Millwood; June 26. mm.; first protarsus .59-.66 mm.; YY.L./ Ontario: Riverhead, Toronto, Orillia; July l'f.L. = 2.00-2.37. 1:3-Aug. 8. Quebec: Aylmer, Norway Bay; Abdomen Aug. (l-19. Tennessee: Reelfoot Lake; Aug. Color pattern as in male except stcrnites 14. wilh no pigmentation. Cerci white to pale Specimens examined, 66. cream. Spermalhecae (figure 14K) heavily sclerotizcd and pigmented, round to ovate; CHAOBORUS (SAYOMYIA} sclerotized and pigmented neck of duct larger than in two preceding species, coni­ ANNULATUS NEW SPECIES cal, straight; diameter of spermathccae Comments .OGG mm. One specimen of this species was re­ 6 LARVA corded by Matheson (1925) as Chaoborus Total length unknown; clear, practically brasiliensis Theobald (= C. festivus Dyar lransparent; eyes purple; tips of mandibu­ and Shannon) . In the key given by Lane lar teeth brown; otherwise all colorless (19l2, 19-13), the specimens here consid­ (slide preparation). Head length unknown; ered run to C. brasiliensis. However, com­ antennae (figure 170) .41 mm., a small parison of the specimen examined by scta (.022 mm. long) located .35 of total ,\,Iatheson and other material that has antenna] length from proximal end; longer come to hand with specimens of C. brasi­ antenna] blades .38 mm. long, shorter licnsis (loaned by the United States Na­ blade .25 mm.; postanlennal filaments .40 tional j\Iuseum) reveals a number of mm.; prelabral appendages (figure 17E) trenchant differences.

0 The larva of this species has not been previously described. However, the author has one slide from the Cornell collections of disseckd parts of the head of a larva v.,-hich is labeled, "ChaolJorus allmtus .Johnson? Collected where albnfu::; abundant, E. N.Y., Townes." '. W c k11ow of only two species of the subgenus Sayornyia in N cw York, C. punctipennis and ( olbntus. This lan·a belong-s to the subgenus Sayomyia quite obviously. It has the proximal st>ta on the antennae; it has no attached tooth on the median mandibular tooth, and it has the apparently hv_o-segme11ted, long, pointed process or1 the ninth segment. In addition it has a pair of very <'Oll­ ~p1cuous setae on the anterior face of the labrurn. It i~ not C. punctipennis since the prelabral appendages resc~mble those of C. flauica11s or C. nyblaei. For this reason it seems safe _to describe what tlwn• is of this larva as C. albat11s. Unfortunately there are no data as to the Iccality nor the habitat of the larYa nor even the date. 39 In C. brasiliensis there is considerable Thorax pigmentation in the pleural areas and the White in ground color with very pale to scutellum is dark brown, while in this spe­ pale brown darkened areas. Anterior pro­ cies there is almost no pigmentation in the notal lobes entirely white; posterior prono­ pleural areas and none in the scutellum. tum with pale brown cloud at upper angle; C. brasiliensis also has a smaller head, scutum with two pairs of pale brown vit­ longer clypeus, and longer wings relative tae; postnotum pale brown; remainder of to head width. In addition, the triangular thorax white, without spots or pattern. spine on the metathorax (subalar process, Pronotal setae 11; proepisternals 5; post­ figure 6A) is obtuse and bare in this spe­ pronotals I; preepisternals 2; anepisternals cies, while in C. brasiliensis it is acute and 9; upper mesepimerals 4. In the paratypes covered at the tip with minute spines. these counts are: pronotals 11-18; proepi­ This species is readily separated from sternals 3-5; postpronotals 1-2; preepister­ other species of the subgenus Sayomyia in nals 2-5; anepisternals 8-10; upper mesepi­ North America by the presence on the merals 3-4. wing membrane of two indistinct, brown bars rather than small discrete brown spots Thoracic appendages (figure 13H). Wings (figure 13H) translucent, milky. marked with two incomplete pale brown Description crossbands and a partial connecting bar forming a short, broad letter H, with.costal FEMALE margin slightly darkened. Wing length 2.00 mm.; wing width .62 mm.; W.L./W.W. Total length 2.50 mm.; paratypes 2.75- = 3.17. In paratypes these measurements 3.00 mm. Antenna! and cranial setae pale are: wing length 1.92-2.07 mm.; width yellowish; thoracic and abdominal setae .62-.70 mm.; W.L.JW.W. 2.88-3.29. Pos­ white; setae of legs white except that those = terior marginal scales of alternating at distal end of tibia brown. General body lengths, the longer .20 mm., the shorter color white, with faint brown pattern on .10 mm. long. In paratypes these are as thorax and abdomen; legs conspicuously follows: the longer .18-.20 mm., the shorter ringed with brown. .086-.10 mm. Head Halteres white; structure and vestiture Head capsule white; pedicel white, with as in C. punctipennis. four long setae (paratypes with three to Leg structure and vestiture as C. punc­ four setae); flagellar segments as in C. tipennis, white, conspicuously marked with punctipennis: proboscis pale brown; maxil­ brown rings, nine on profemur, seven on lary palpi, including second segment, protibia; tarsi with brown apices, except brown; setae of head capsule more sparse for last segment. Legs relatively longer than in C. punctipennis, a single row of than in C. punctipennis; profemur IA0 long setae and a single row of small setae mm.; protibia 1.40 mm.; first protarsus .55 extending anteriorly on each side of coro­ mm. Tarsal segments are missing in type nal stripe. so total leg length cannot be given for this Head width .61 mm.; width between specimen. In paratypes the measurements eyes .IS mm.; length of prementum .20 are as follows: profemur 1.29-1.40 mm.: mm.; length of clypeus .17 mm.; H.W./ protibia 1.29-1.40 mm.; first protarsus .51- W.B.E. = 3.30; H.W./P.L. = 3.07; H.W./ .55 mm. Total length of prothoracic leg C.L. = 3.58. In the paratypes these meas­ 3.96-4.11 mm.; mesothoracic leg 2.85-2.96 urements are: head width .60-.62 mm.; mm.; mctathoracic leg 4.70-4.81 mm.: width between eyes .17-.20 mm.; length W.L./Pf.L. = 1.42. In paratypes this ratio of prementum .17-.20 mm.; length of cly­ is 1.44-1.60. Pulvilli slightly larger and peus .14-.18 mm.; H.W./W.B.E. = 3.10- with longer sctae than C. punctipennis, 3.50; H.W.JP.L. = 3.23-3.66; H.W.JC.L. = setae of pulvilli attaining middle of claws. 3.66-4.40. Claws as in C. punctipennis.

40 Abdomen between the eyes is relatively greater. A Ground color white; tergites 1 and 2 distinct coronal suture is present. The head with conspicuous lateral brown triangular capsule sclerotization has not expanded be­ patches extending toward midline; seg­ neath the foramen magnum, and the ar­ ments 3-7 with tergites much less pig­ ticulations of the maxillae are in their mented and pigmentation confined largely primitive position immediately ventrad of to lateral margins and anterior third; ster­ the posterior tentorial pits (figures 19A, nites 1-5 white; sternite 6 with brown pig­ 19B). mentation medially; sternites 7 and 8 The antennae differ from those of Chao­ largely pale brown. Genitalia as in C. borns in that the first antenna! segment is punctipennis; cerci white with short setae. larger and bears a cluster of setae in the Spermathecac (figure 140) spherical with females but not in the males. The second a slender neck; diameter .060 mm. in both antenna! segment (pedicel) is thickly be­ holotype and paratypes. set with long setae in the females but not the males. Specimens Examined The mouthparts (figures 19C, 19D, 19E) are fundamentally identical with Holotype c;i, Crystal River, Citrus those of Chaoborns. In Moch/onyx the la­ County, Florida, September 18, 1950, Light cinia is larger, is toothed along both the Trap, Hudson; 12 'i"i' paratypes, data as inner and outer edges, and is stoutly sclero­ above; 1 Cjl paratype, Miami, Dade County tized although unpigmented. The maxil­ (36th Street Light Trap), December 9, lae articulate with the head capsule im­ 1947, W. Buren; 1 Cjl paratype, Miami mediately vcntrad of the posterior ten­ Beach, Dade County, December 15, 1947; torial pits. 1 c;i, Miami, Dade County, December 9, M ochlonyx lacks a sensory pit in the 1947, W. Buren; 2 'i"i', Morrison Field, second segment of the maxillary palpus. West Palm Beach, October 5, 1942, D. E. The labium is as in Chaoborns except the Hardy; 2 'i"i', Lake Worth, Aug. 6, 1951, prementum is relatively shorter. In the W. W. Wirth. Georgia, 1 c;i, Billy's Island, chaetotaxy of the head, the only essen­ Okefenokee Swamp, June 1912. tial difference is that already noted in the Total specimens examined, 21. first two antenna! segments of the females. Holotype and 12 paratypes in the col­ The thorax of M ochlonyx (figure 20A) lection of the United States National Mu­ is shorter and deeper than that of Chao­ seum; two paratypes in collection of the borus. In addition, the anterior protho­ University of Minnesota. racic lobes of the females are not separated by the anterior expansion of the mesotho­ THE GENUS MOCHLONYX racic tergum but are continuous from one side to the other. The median portion of LOEW the prothorax bears numerous long sctae. In the males, the prothoracic lobes are Mochlonyx Loew, 1844, Ent. Zeitung, Stet­ much as in Chaoborus with only a narrow tin, p. 121, footnote. strip of sclerotization connecting them dor­ Type: Corethra velutina Ruthe. sally. There are no setae on the area be­ tween the pronotal lobes in the males. The Morphological Considerations pleural apophyseal pit is not as complex in Adults of the genus Moch/onyx arc very structure as in Chaoborus, and the me­ similar to the adults of Chaoborus in all tanotal process and the subalar process are general morphological features and differ lacking. from them only in some details. The mem­ In chaetotaxy M ochlonyx differs from bers of this genus are more primitive in Chaoborns in the presence (in the case of structure than Chaoborus. M. cinctipes and "fl;f. vefotinus but not of The head (figure 19) is wider in both M. fuliginosus) of one to seven setae on sexes than in Chaoborus, and the width katepisternum 3. Similar vittae are pres-

41 ent on the mesonotum, and there are simi­ sclerites also bear regular rows of micro­ lar microsetae on the whole thoracic sur­ setae, and the membranes are closely beset face. The medial selae of the mesonotum with patches of microsetae, four to five per are short, while the lateral and posterior patch. setae are quite long. The scutellum bears The spiracles are more readily discern­ two to four transverse rows of long setae, ible than in Chaoborus. They arc simple and the postnotum is bare. and circular. The spiracle of segment 7 The most apparent difference between is twice as large as the preceding spiracles these two genera in the adults is in the in the male and 2.5 to 3 times larger in size of the first tarsal segment (figure the female. 20B) . In M ochlonyx the first tarsal seg­ The female genitalia (figure 21C) are ment in both sexes is only one-fourth the similar to those of Chaoborus with the ad­ length of the second segment. dition of a small sclerite located ventrally An additional appendage difference is immediately anterior to the gonopore. This apparent in the last tarsal segments of the sclerite (sigma of culicidologists) is a males. On the last tarsal segments of the sinuate, undivided structure with a par­ males of 111. velutinus and M. cinctipes tially serrate posterior margin in M. velu­ and the prothoracic and mesothoracic legs tinus, while in M. cinctipes and M. fuligi­ of the males of M. fuliginosus, there is a nosus it is divided medially and quite well developed, setaceous lobe located smooth posteriorly. This sclcritc should be proximally and posteriorly. a fragment of the posterior part of sternite The claws in ,W ochlonyx are large and 8, but it is laterally continuous with complex. In the males of M. velutinus and sternitc 9 and may, therefore, be a sec­ M. cinctipes (figure 20D) each of the two ondary sclerotization of the intersegmental claws bears a long medial tooth and a membrane between sternites 8 and 9. rather variable but usually long, serrate There are three spermathecae as in Chao­ basal tooth. In the males of M. fuliginosus borus. the claws of the prothoracic and mesotho­ In the male genitalia (figures 21A, 21B, racic legs are identical with those in the 21D, 21E, 21F, 21G, 23D) the most ap­ two preceding species, but those on the parent differences are the presence of a metathoracic leg arc simple, with only a short stout seta at the apex of the gono­ small setalike projection at the base. style and the fact that segment 8 is half In the females of all species the proximal as long as segment 7. In addition, the penis lobe is absent, and there is on each claw a valves (figures 21 A, 21F, 23D) are large single long, basally serrate, proximal tooth. and simple, with no enlargement of the There are no pulvilli, although a branched, free end or head. The male genitalia are setalike empodium is present. The legs arc rotated 180° as in Chaoborus. all approximately equal in length, with the The greatest difference between Moch­ metathoracic leg slightly longer. There are lonyx and Chaoborus is evident in the no tibial spurs, and the legs are all densely larvae. The larvae of 111 ochlonyx arc recog­ covered ,Yith rather short setac. nizably Culicidae. The head (figures 22A, There is little difference in wing struc­ 22B) is much broader than in Chaoborus, ture from that in Chaoborus (figures 20E, and the antennae, although prehensile, arc 20F) . The haltcres of these two genera widely separated. show striking differences in the setal arma­ A large conspicuous clypeus defined by ture. In M ochlonyx (figure 20C) the setae clearly marked clypeofrontal sutures oc­ are numerous on the capitulum, and there cupies the median portion of the head from are even a few on the pedicel. the antcriormost margin to the foramen The abdominal segments in the male arf: magnum. shorter than in Chaoborus, only slightly From the membranous area between the longer than in the female. The sclerites clypeus ancl the labrum there arise one are covered with long sctae but lack the pair of lateral and two pairs of median regular marginal rows of Chaoborus. The setae. The lateral setae (figure 22A), lo-

42 catcd at the outer anteriormost corners of sule below the antenna! foramen. The pos­ the clypeus, are long and simple. The two terior articulation is to the ventral wall median pairs of setae (figures 22A, 22C) of the head capsule immediately anterior bear small, simple spines and larger, to and laterad of the maxilla. branched spines medially. These setae are The maxilla (figure 22G) consists of a probably homologous to the postantcnnal single lobe, the stipes, and a short one­ filaments and/or the prelabral appendages segmented palpus. The stipes bears a lat­ of the larvae of Chaoborus. eral and a medial tuft of bladelike setae The labrum (figures 22B, 22D) projects with serrate tips. Between these setal tufts ventrally and posteriorly from the anterior there is a long stout spine with a bifurcate edge of the clypeus. It is considerably tip. The palpus is armed with a single, larger than the labrum in Chaoborus and stout seta and two small setae. is somewhat triangular in outline. Just an­ The labium (figure 22F) is much re­ terior to the middle there arc three pairs duced. The submcntum is vestigial, and of setae, with the middle pair considerably the prementum is a single small median longer. The dorsal surface of the apex of lobe which is fringed aborally with a short the labrum is covered with an imbrication and a long row of doubly serrate setae. of short, stout, flattened sctae (figure The anterior or oral margin of the ventral 22D). These setae are apically two- to wall of the cranium (maxillary segment) is five-forked. fringed with a dense cluster of short, There is a medial sclerotizcd band in bladelike setae with serrate tips. which on the palatal surface of the labrum The thorax and abdomen (figure 23A) is a pair of lateral pockets opening anter­ offer little contrast to those of Chaoborus. iorly (figure 22D). Within each of these A siphon is present on the posterior part pockets is a fan of seven flattened, stout of abdominal segment 8. This siphon is setae which arc distally serrate on both typically culicid and has a pair of sides. These fans are in all probability branched setae on either side of its base. homologous to the messorial fans of the The tracheal system is fully developed in Culicinae and to those lateral fans which this genus, but paired enlargements oc­ occur at the labral apex 111 Chaoborus cur in abdominal segment 7 and in the larvae. thorax. The tentorium consists of a pair of The anal segment bears a ventral and a stout rods that pass through the head dorsal brush as in Chaoborus. Both of capsule from points apparently posterior these brushes are composed of long­ to the antenna! foramina near the anterior plumose sctae (figure 23A). There are mandibular articulations (figure 23B) to four anal papillae, and the anal appa­ the lateral margins of the foramen mag­ ratus is similar to that of Chaoborus, lack­ mnn posteriorly (figure 22A). ing only the large ventral hooks. The moulhparts are somewhat less re­ The pupae of Mochlonyx resemble those duced than in Chaoborus. The mandibles of Clwoborns in most features. They differ (figure 22E) arc large and well sclcrotizcd. chiefly iu the respiratory horns, the anal ,\t their anterior margin they bear a fan paddle, and the general shape of the ab­ of seven setae which is homologous to the dominal segments. mandibular fan of Chaoborus. Posteriorly The respiratory horn (figure 23C) is lhere arc seven to eight stout, well pig­ relativclv more slender than that of Chao­ mented teeth. These teeth arc preceded by borus; tl1e aperture is located at the apex four peclinate setae, the base of each being of the main body of the horn. The ab­ parlially surrounded by a short, concave dominal segments are shorter and broader spine. Earlier inslars show only two or than in Clrnoborus; they are drawn out three of these pcctinate sctae. into narrowly rounded lobes, each bearing The anterior mandibular articulation a pair of lanccolate sctac at the latcro­ (lig-urc 23B) is on a process projecting posterior angles (figure 23C) . The anal from the ventral margin of the head cap- paddles (figure 23C) are more rounded 43 posteriorly than in Chaoborus, and the Comments membrane is gradually thicker and more sclerotized progressing from the central This species is readily distinguished portion toward the edges. The median sup­ from other species in the genus by its uni­ porting rib is present. colorous wing scales and by its reddish­ brown to black scutum. In the females the sclerite sigma is undivided, while in Taxonomic Considerations M. cinctipes and M. fuliginosus it is com­ The genus M ochlonyx was established posed of two pieces. by Loew in 1844 with Corethra velutina The species is widely distributed in Ruthe as the type. This is a synonym of North America from New Jersey, northern Tipula culiciforrnis DeGecr. However, De­ Illinois, north central Colorado, and the Geer's T. culiciforrnis is a primary homo­ Uintah Mountains in Utah and north into nym of T. culiciforrnis L. (1767). The northern Quebec, Northwest Territories, next available name for the type species the Yukon, and Alaska. It has not been is apparently Corethra velutina Ruthe collected on the Pacific Coast except in (1831) originally designated by Loew. Ed­ Alaska. wards' opinion (1920, 1930) that Moch­ The larvae are found early in the spring, /onyx is the valid name for this genus usually in semipermanent or temporary is here accepted. ponds and pools.

Description MOCHLONYX VELUTINUS MALE (RUTHE) Total length 4.50-6.00 mm. Setae of Tipula culiciforrnis DeGeer, 1776, Mem­ antenna! whorls light brown; setae of oires pour Servir a l'Histoire des Insects, vertex pale yellowish; setae of clypeus and 6:372. maxillary palpi dark brown; remaining setae pale yellowish, except dark brown [non] Tipula culiciforrnis Linnaeus, at distal ends of femora and proximal ends 1767, Systema Naturae, ed. 12, of tibiae. General coloration pale yellow­ 1(2):978. brown to light brown, with mesothoracic Corethra velutina Ruthe, 1831, Isis 8:1205. scutum pale reddish-brown to dark red­ Corethra karnerensis Felt, 1904, N. Y. dish-brown to nearly black. State Mus. Bui. 79, pp. 347-353, figs. Head 83-91. Johannsen, 1934, Cornell Agr. Expt. Sta. Mem. 164, p. 40 (Moch­ Head capsule pale brown, somewhat lonyx). darkened over vertex; pedicel dark purp­ lish-brown in northern and western forms Corethra lintneri Felt, 1904, ibid., pp. and pale yellowish-brown in eastern forms. 353-356, figs. 92-96. Johannsen, 1934, bare of setae. Flagellar segments with nar­ ibid., p. 40 (Moch/onyx). row, dark basal ring; black at setal whorl; Corethra culiciforrnis (DeGeer), Dyar and somewhat darkened apically. Clypeus light Shannon, 1924, lnsecutor lnscitiae Men­ brown, darker around margins; stipites, struus 12:206-207. Matheson, 1925, palpi, prementum, and sclerotized portions Canad. Ent. 57:1.59. of labellae brown. Moch/onyx culiciforrnis (DeGeer), Mar­ Head width .88-1.07 mm.; width be­ tini, 1929, in Lindner, Die Fliegen der tween eyes .44-.57 mm.; length of premen­ Palaearktischen Region, Bd. 3, Fasc. 11, tum .18-.24 mm.; length of clypeus .21- 12, pp. 46-47. Edwards, 1932, Genera .24 mm.; penultimate antenna! segment Insectorum, Fasc. 194, p. 22. Matheson, ]pngth .28-.35 mm.; ultimate antenna! seg­ 1944, A Handbook of the Mosquitoes ment length .20-.24 mm.; H.W./W.B.E. = of North America, Comstock Pub. Co., 1.82-2.09; H.W./P.L. = 4.35-.5.00; H.W./ Ithaca, N. Y., p. 93, pl. 11, fig. 3. C.L. = 3.77-,l.44; Pu.L./U.L. = 1.29-1.'12. Thorax FEMALE Thorax light to dark reddish-brown to Total length 4.00-5.50 mm. General col­ nearly black and, owing to microsetae, oration often much paler than associated pruinose. Pronotal setae 24-37; proepister­ males. Seta! coloration and chaetotaxy nals 6-12; postpronotals 3-11; preepister­ identical with that of male with exceptions nals 4-13; anepisternals 7-13; upper mesepi­ noted below. merals 13-22; parascutellars 3-6; katepi­ Head sternals 0-8 (specimens from southern part First antenna! segment with 10-12 setae; of range with no more than one, northern second antenna! segment pale yellowish­ specimens with five to eight) . brown, thickly beset with yellow setae. Thoracic appendages Head width .92-1.11 mm.; width between Wings (figure 20F) unmarked, translu­ eyes .46-.58 mm.; prementum length .20- cent, pale to slightly infuscated; length .25 mm.; clypeus length .20-.25 mm.; 3.H-4.11 mm.; width .74-1.03 mm.; W.L./ H.W./W.B.E. = 1.90-2.12; H.W./P.L. = W.\V. = 3.95-4.30. The longer posterior 01.33-4.64; H.W.jC.L. = 3.82-4.64; ultimate marginal scales .168-.178 mm. long, the segment of antenna slightly longer than shorter scales .068-.071 mm. long; vein Cu1 penultimate. as in Sayomyia. Thorax Legs pale yellowish-brown, apices of Thorax often much paler than in males; femora darker brown, last tarsal segments pale yellowish to brown in pleural areas dark brown; covered with short, pale setae, with light reddish-brown to dark reddish­ these setae dark at apices of femora and on brown mesonotum, scutcllum, and postno­ last tarsal segments, setae long on meso­ tum. :Median area of pronotum thickly thoracic and metathoracic tibiae. Profemur covered with long, yellow setae. Pronotal length 1.59-1.92 mm.; protibia length 1.70- setae (on lateral lobes) 44-56 (approx.); 1.96 mm.; first protarsus .18-.25 mm.; proepisternals 8-13; postpronotals 8-15; W.L./Pf.L. = 1.90-2.13. Claws yellowish­ preepisternals 5-20; anepisternals 10-17; brown. upper mesepimerals 19-29; parascutellars Halteres pale grey-brown, capitulum 3-5; katepisternals 1-5. darker. Thoracic appendages Abdomen Wing length 3.24-4.25 mm.; wing width Ground color of abdomen grey, central 1.00-1.33 mm.; W.L./W.W. = 3.16-3.37; portion of each segment brown; brown W.L.jH.W. = 3.40-3.84; r-m distad of area of sternites, in general, smaller than m-cu (figure 20F). lha t on tergi tes. Halteres (figure 20C) identical with Genitalia (figures 21A, 21B, 21D) those of male. Legs essentially identical in Posterior half of tergi te 8 and of stcrnite structure except for ultimate tarsal seg­ ti with numerous long sctae. Tcrgite 9 ment. Color of legs as in male except dis­ (figure ,!ID) produced into a slender tal one-half of each femur with brown spinelikc process, basally somewhat bi­ setae. Profemur 1.55-1.88 mm.; protibia lobed each lobe with from 11-22 long 1.62-2.07 mm.; first protarsus .22-.29 mm.; selae.' Sternile 9 much reduced, sclerotiza­ W.L./l'f.L. = 2.01-2.27. tion limited to a narrow band across an­ Abdomen terior margin. Gonocoxites (figure 21A) Sclerites often paler than in male; ter­ brown; gonostyles brown, one-third to al­ gites pale brown to brown; sternites most one-half shorter than gonocoxitcs, lighter, yellowish-brown. Cerei (figure strongly sclerotized; penis valves (figures ':.!lC) colored as abdominal sclerites, cov­ '!IA, 21B) dark brown, strongly sclero­ ered with short sctae as in Chaoborus; lized, slender apically, bifurcate basally, spcrmathecac heavily pigmented, dark much longer than in Chaoborus. Coxite brown, somewhat ovoid in shape, with l('ngth .M-.50 mm.; style length .25-.31 short, pigmented neck leading to duct, di­ mm.; Co.L./St.L. = 1.59-1.9-k ameter .07-.10 mm. 45 LARVA (figures 22, 23A, 23B) yellowish-brown. Respiratory horns ~pin­ Total length (last instar) 7.00-9.00 dleshaped, length .69-.85 mm., four times mm.; pale grey to yellowish-brown, trans­ longer than greatest diameter. Abdominal lucent; head brown, siphon pale brown, segment 7 almost twice as long as preced­ eyes dark brown, nearly black; setae pale ing segment; segment 8 one-quarter length yellow to brown; mandibular teeth _dark of 7. Tergite 7 with four pairs of plumose brown to black, fringing setae of maxillary setae posteriorly, one pair of simple setac segment dark brown. Tracheal air sacs medially, and a pair of stout lanceolate of thorax and abdominal segment 7 cov­ setae at each latero-posterior angle. Anal ered dorsally with grey pigment cells. paddle with medial rib bearing a simple seta at distal end and plumose seta one­ Head (figure 22) fourth of rib length from distal end. Head length .70-.88 mm.; head width 1.07-1.37 mm.; antennae .26-.33 mm. long, Specimens Examined with four long, bladelike setae and a mi­ Alaska: Anchorage, McKinley Park; nute, proximal seta; the three longer, api­ June 19. Alberta: Banff; July 12-13. British cally blunt, antenna! blades .40-.51 mm. Columbia: Kalso, Mile 255-Alaska-Rich­ Jong, the acute blade one-third shorter; ardson Highway; June 3-13. Colorado: clypeolabral setae equal to antenna! blades Jackson County, Grand Lakes; June 2[;­ in length. Medial two pairs of clypeolabral July 16. Connecticut: Suffield; May H. setae with short, simple and branched Illinois: Antioch; ,June 8. Massachusetts: spines located variously from apex to tip, Amherst, Northampton, Springfield, Cush­ usually medially and on lateral face. Lat­ mans Pond (larvae, April) ; May 16-20. eral pair of setae simple. Manitoba: Churchill, Gillam; July 15-Aug. Head capsule with one pair of stout, 20. Minnesota: Itasca State Park, Cloquet, simple setae on posterior margin of dorsal Carlton County, Finland, St. Louis side, an additional pair anteriorly, mesad County, Vineland, Virginia (larvae and of eyes, and a pair of plumose setae an­ adults); May 8-June 17. Montana: Glacier terior to the latter between clypeus and National Park, Whitefish, Two Medicine eyes. Clypeus with three pairs of plumose Lake; May 18-July 8. New Hampshire: setae on anterior third. Labrum (figure Dublin Jeffrvs Franconia: April-May. 22D) with two pairs of small setae and New J~rsey: Lahaway. New York: Eliza­ one pair of long setae midway along length bethtown. Ithaca, Karner, Ringwood, Old near lateral margin of aboral surface. Forge, Castile, Lake Champlain; May 17- Thorax and abdomen (figure 23A) Aug. 27. Northwest Territories: Norman Setae of thorax plumose, short. Thorax Wells, Sawmill Bay, Yellowknife (larval stout, segmentation obscure except for and pupal skins and adults); June 11- setal pattern; air sacs of thorax elongate. July 19. Ontario: Ottawa, Arnprior; May Abdominal setae plumose, abdomen other­ 21-July 9. Quebec: Broadview, Aylmer, Ft. wise without distinguishing characteristics. Chima (larval and pupal skins and Segment 7 one-half longer than preceding adults); May 21-July 29. Saskatchewan: segments; air sacs in segment 7 spindle­ Waskesiu; June 15. Utah: Uintah County shaped, large. Segment 8 with dorsal si­ (larvae and adults); June 17-July 15. phon, .70-.81 mm. long, four times longer Wyoming: Yellowstone Park; June 30. than wide. Siphon with two basal plumose Yukon Territory: \Yhitehorse (larval and setae. Segment 9 bare of setae and with no pupal skins and adults); June 13-July 18. dorsal process. Last abdominal segment Specimens examined, 478. with an anal fan composed of 28-30 long­ plumose setae: a cluster of four long-plu­ MOCHLONYX CINCTIPES mose setae on posterior dorsal margin. PUPA (figure 23C) (COQUILLETT} Total length 6.00-7.00 mm.; cephalo­ Corethra cinctipes Coquillett, 1903, Canad. thorax almost half total length. Color pale Ent. 35:190. Felt, 1904, N. Y. Stale

46 Mus. Bui. 79, pp. 356-357, pl. 28, fig. 1, Head text fig. 97. Dyar and Shannon, 1924, Head capsule pale yellowish-brown; Insecutor Inscitiae Menstruus 12:208. pedicel slightly darker, somewhat pruinose; Matheson, 1925, Canad. Ent. 57:159. flagellar segments darkened at setal whorl Corethra cinctipes, var. obscura Dyar and and for a short distance distad of whorl. Shannon, 1924, ibid., p. 208. All head structures pale yellow-brown. (Coquillett), Ed­ M ochlonyx cinctipcs Head width .90-1.14 mm.; width be­ wards, 1932, Genera lnsectorum, Fasc. tween eyes A2-.57 mm.; length of premen­ 191, p. 22. Johannsen, l93t, Cornell tum .U-.22 mm.; length of clypeus .15-.22 A.gr. Expt. Sta. Mem. 164, pp. 40-41, mm.; penultimate antenna! segment length pl. 16, figs. 151-157. Matheson, 19-14, A .25-.3"1 mm.; ultimate antenna! segment Handbook of the Mosquitoes of North America, Comstock Pub. Co., Ithaca, length .20-.22 mm.; H.W.jW.B.E. = 1.85- N. Y., p. 93, pl. II, fig. 2. 2.IO; H.W./P.L. = 4.81-6.30; H.W./C.L. = ,k33-5.72; Pu.L./U.L. = 1.22-1.50. Comments Thorax 1W ochlonyx cinctipes is a strictly N earc­ Thorax yellow-brown, with a greyish tic species which is rather widely but pruinose appearance. Scutellum with nu­ sparsely distributed across the northern merous long and short setae in several part of the continent. The adults are much irregular transverse bands. Pronotal setae less variable in both size and color than 26-43; proepisternals 15-28; postpronotals JI. velutinus and are quickly distinguished 10-19; preepisternals 12-22; anepisternals from that species by their yellowish-brown 10-29; upper mesepimerals 8-18; parascu­ color, by their lack of the conspicuous red­ tcllars 1-4; katepisternals none. dish-brown to black color on the mesono­ tum, and by their mottled-appearing Thoracic appendages wings. Wings mottled (figure 20E) , color pat­ The prementum and clypeus are rela­ tern formed by light and dark scales. Wing tively shorter and the wings wider in the membrane without spots, translucent, pale males than in 1vl. velutinus, and both the to slightly infuscated; wing length 2.77- males and females have more numerous 3.66 mm.; wing width .72-1.07 mm.; W.L./ thoracic setae, particularly proepisternals W.W.= 3.41-3.86. Longer posterior mar­ and prcepislernals. The females, further­ ginal scales .121-.142 mm.; shorter scales more, have a wider head relative to wing .067-.071 mm. length. Legs pale yellowish-brown, distal ends Larvae have always been found very of femora with a pale ring covered with early in the spring and always in tempo­ pale setae, a dark ring bearing dark setae rary pools. immediately proximad, followed by an­ Description other pale ring proximad of latter; tibiae MALE with a pale yellowish ring proximally, fol­ lowed distally by a dark ring; tarsal seg­ Total length 4.00-5.50 mm. Setae of ments l, 2, and 3 with pale proximal rings antenna! whorls pale yellow-brown; setae bearing pale yellowish sctae. Profemur of vertex yellowish; setae of clypeus and length lA0-1.96 mm.; protibia length 1.48- maxillary palpi pale brown; remaining se­ 2.03 mm.; first protarsus .18-.25 mm.; tae of head, thorax, and abdomen very W.L./Pf.L. = 1.81-1.98. pale yellowish-brown. Setae of legs pale Halteres yellow-brown, uniform from brown except for ring of yellow setae near scabellum to capitulum. distal end of each femur, near proximal end of each tibia, and at proximal ends of Abdomen tarsal segments l and 2. General colora­ Ground color of abdomen yellow-brown, tion yellowish-brown; mcsothoracic scutum central portion of each sclerite somewhat no darker than pleural areas. darker, resulting in a ringed appearance. 47 Genitalia LARVA AND PUPA Genitalia much like those of M. velu­ The immature stages of this species tinus. Tergite 9 (figure 21E) produced cannot be distinguished from those of M. into a short, stout process posteriorly, velutinus. lobes at base of tergite 9 each bearing 20- 24 long setae. Gonostyle (figure 21G) Specimens Examined with one to several moderately long setae Alabama: Camp Rucker; Mar. 5. Connec­ on inner face near base in addition to mi­ ticut: Suffield; May 14-16. Massachusetts: nute setae scattered along full length; penis Amherst, Northampton, Springfield; May valves (figure 21F) larger and stouter 4-28. Minnesota: St. Paul, Itasca State than in M. velutinus. Coxite length .44- Park; May 20-31. Montana: Glacier Na­ .50 mm.; style length .22-.31 mm.; Co.L.j tional Park; April 28-May 17. New Hamp­ St.L. = 1.52-1.93. shire: Dublin; May. New York: Ringwood FE:MALE Hollow, Ithaca (larvae), Delmar, Karner. Dryden; May 10-June 3. Oregon: Oakville, Total length 4.00-4.50 mm. General Corvallis; March 28-April 17. Quebec: Gat­ coloration and structure as in male with incau Point; May 19-June 7. Virginia: Mt. exceptions noted below. Vernon; April 20. Washington: Hoodsporl, Head Port Madison; April 23-May 7. Washing­ First antenna! segment with 8-12 long ton, D. C.: May 19. setae, second antenna! segment thickly Specimens examined, 129. beset with long pale setae. Head width 1.07-1.17 mm.; width between eyes .47-.57 MOCHLONYX FULIGINOSUS mm.; prementum length .22-.25 mm.; cly­ peus length .22-.25 mm.; H.W./W.B.E. = {FELT) 2.05-2.35; H.W./P.L. = 4.55-4.82; H.W./ Corethra f11,liginosus Felt, 1905, N. Y. C.L. = 4.55--1.93. State Mus. Bui. 97, p. 458. Dyar and Thorax Shannon, 1924, Insecutor Inscitiae Men­ ::\Iorphologically the thorax is as in M. struus 12:207. Matheson, 1925, Canad. veliitinus females. Pronotal setae (lateral Ent. 57:159. lobes) 62-71; proepisternals 26-33; post­ M ochlonyx fuliginosa (Felt), Edwards. pronotals 17-20; preepisternals 20-28; an­ 1932, Genera Insectorum, Fasc. 194, p. episternals 16-36; upper mesepimerals 15- 22. Matheson, 19-H, A Handbook of the 22; parascutellars 2-5; katepisternals 5-8. :Mosquitoes of North America, Com­ Thoracic appendages stock Pub. Co., Ithaca, N. Y., p. 93, pl. Female wing (figure 20E) often some­ 11, fig. 1. what darker than in male. Wing length Comments 3.14-4.14 mm.; wing width 1.00-1.40 mm.; This is a very rare species in collections. W.L./W.W. = 2.94-3.22; W.L./H.W. =---= It was originally described from a single 2.65-3.44. Scales of wings broader than in female collected at Nassau, New York on male and also broader than in females of June 12, 1905, and the author has presum­ 11;[. velutinus; r-m but slightly distad of ably this specimen. In addition to this m-cu. only four male specimens from New York Profcmur length 1.66-1.96 mm.; protibia and two from Massachusetts have been 1.85-2.07 mm.; first protarsus .29 mm.; examined. W.L./l'f.L. = 1.88-2.11. A comparison of the genitalia of the Abdomen male of this species with the genitalia il­ Cerci pigmented as abdominal segments, lustrated by Martini (1929, p. 47, text coverP

48 liginosus (Felt) and that this species is velutinus except spur of Cu2 extends also holarctic although sparsely distrib­ farther toward Cu1 at distal end. uted. Legs pale, unicolorous, greyish-yellow; This species is readily separated from sizes as in M. velutinus except metatho­ either of the preceding species by the racic leg only two-thirds diameter of pro­ small number of thoracic setae in both thoracic and mesothoracic legs; densely sexes, and in the males by the lack of a covered with rather short, pale setae. Pro­ lobe on the last tarsal segment of the femur length 1.66 mm.; protibia length metathoracic leg. 1.66-1.70 mm.; first protarsus length .18 mm.; W.L./Pf.L. = 1.51-1.57. Claws pale Description yellowish; last tarsal segment and claws of prothoracic and mesothoracic legs as in MALE M. velutinus (with basal lobe on tarsal Total length 4.00-5.00 mm. Setae of segment, and each claw with a median antenna! whorls pale grey; remaining setae and basal tooth) ; last tarsal segment of pale yellowish or sordid white. General metathoracic leg without a basal lobe and coloration pale greyish-yellow. with simple claws. Halteres pale greyish-yellow. llead Head capsule pale greyish-yellow, Abdomen slightly darkened over vertex; pedicel with Ground color of abdomen pale greyish­ slight brown cast, bare of setae; flagellar yellow, central portion of each tergite segments slightly darker from whorl to slightly darker, giving a somewhat banded distal end, transparent and pale from effect; sterni tes paler than tergites. proximal end to whorl; head, clypeus, Genitalia ( figure 23D) labium, and maxillary palpi pale greyish­ Tergite 9 not at all produced posteri­ ycllow; sctae appear in same regions and orly, with 15-17 long setae on either side; arc of comparable size to those in pre­ stcrnite 9 much reduced, with only a nar­ ceding two species but are much more row band of sclerotization across anterior sparse. margin. Gonocoxites with six stout setae Head width .70-.8.J, mm.; width between on inner face near apex; gonostyles pale, eyes .31-.35 mm.; length of prementum two-thirds as long as gonocoxites, strongly .10-.11 mm.; length of clypeus .H-.15 mm.; sclerotized, with a few fine, minute setae penultimate antenna! segment length .20- along entire length . .21 mm.; length of ultimate antenna] seg­ Penis valves pale, transparent, distal ment .15-.20 mm.; H.W./W.B.E. = 2.22- portion very short, basal portion much 2.:36; H.W./P.L. = 7.00-7.30; H.W./C.L. = larger, rather blade-shaped. Coxite length U5-5.90; Pu.L./U.L. = 1.05-1.27. .41-.-13 mm.; style length .32-.33 mm.; Thorax Co.L./St.L. = 1.26-1.30. Thorax pale greyish-yellow, somewhat FEMALE pruinose. Scutellum with two irregular transverse rows of long setae. Pronotal Total length 3.50 mm. (approximately). setae 18-H; proepisternals 2-3; postpro­ Color as in associated males. Anatomically notals l; preepisternals 2-4; upper mesepi­ as in males with exceptions noted below. merals 3; parascutellars 1-2; anepisternals Head none. The only female specimen of this spe­ Thoracic appendages cies available to the author has been de­ Wings unmarked, clear, pale; length capitated. For this reason the original de­ 2.51-2.(i2 mm.; width .59-.62 mm.; W.L./ scription is here cited, "Proboscis very W.W. = -tOOA.4.J,. Posterior margin of short, pale yellowish. Palpi fuscous yel­ wing with lanceolate scales; the longer low ... Antennae ... pale yellowish; .l-t2 mm. long, the shorter .071 mm.; scales basal segment subglobular, fuscous in­ of wing veins slender; venation as in M. ternally, others brownish with sparse basal whorls and a scanty clothing of pale yel­ Morphological Considerations lowish hairs. Occiput rather thickly clothed This is the largest of the Chaoborinae, with purplish-brown hairs." the larvae attaining a.length of 14.00-16.00 Thorax mm., the adults attaining a length of 9.00- The thorax has also been damaged on 10.00 mm. l\Iorphologically the adults of the single available specimen, and the de­ Encorethra are very similar to the two scription of this must be incomplete. genera already considered. This genus is Postpronotal setae l; preepisternals 7; closer in most features ( thoracic struc­ anepisternals none; upper mesepimerals 2; tures, claws, genitalia, and larval struc­ parascutellars l; katepisternals none. tures) to lt1 ochlonyx than to Chaoborns. Thoracic appendages The head (figures 24A, 24B) resembles Wing length 3.14 mm.; wing width .81 M ochlonyx in the lack of the postgenal mm.; W.L./W.W. = 3.86; r-m distad of bridge, coronal stripe, and sensory pit on m-cu. the second segment of the maxillary pal­ Legs alike in both sexes except for ulti­ pus. The females also resemble M ochlonyx mate tarsal segment and claws. Last tarsal in the presence of a few setae on the mesa! segment of prothoracic and mesothoracic surface of the first antenna! segment. legs with no proximal lobe, claws with but The second antenna! segment of the a single basal process; claws of metatho­ males has a few setae. The eyes are large racic leg almost as in male, with only a and reniform, half surrounding the anten­ slight basal tooth on each claw. Legs rela­ na! foramina. The clypeus is much longer tively shorter than in male. Profemur l.85 than in any of the other genera, almost as mm.; protibia 1.97 mm.; first protarsus .22 long as the head capsule height. The pre­ mm.; W.L.jPf.L. = 1.70. mentum is relatively short and is confined Abdomen to the distal end of the rostrum, the proximal end of the rostrum being oc­ Chactotaxy and coloration as in male. The female genitalia of this specimen have cupied by the greatly elongated stipites been removed and cannot be described. and the membranes between the latter. This particular feature serves to separate LARVA and PUPA the adults of this genus from the other ehaoborinc genera at a glance. Unknown. The mandibles (figure 24C) are well developed, bladelike, and heavily sclero­ Specimens Examined tized. The anterior mandibular articulation New York: l 'i', Nassau, June 12, 1905; I is to a small sclerotized plate which is J, Big Moose, June 14, 1905 (slide mount­ very intimately fused to the antero-lateral ed); 2 '33, Big Chief, June 15, 1905 angles of the clypeus. The posterior articu­ (pinned); 1 J, Moody, iss. Aug. 4, H. G. lation is, as in the two preceding genera, Dyar. Massachusetts: l o, Mt. Tom, May to the sclerotized margin of the cibarium. 14, 1903, F. Knab; 1 J (slide mounted), The maxillae are well developed (figure Springfield, July 18, 1903, F. Knab. The 2-tD). The cardo is small and triangular specimen from Big Moose, New York is and articulates to the head capsule sclero­ here designated as the allotype. It is in the tization mcsad of the posterior tentorial Cornell University collections. pit. The stipes is slender proximally but expands distally to provide a broad base for the attachment of the lacinia and the THE GENUS EUCORETHRA maxillary palpus. The small detached por­ UNDERWOOD tion of the stipcs, which simulates a pal­ pal segment, is present in this genus as Encorethra Underwood, 1903, Science 18: in the two preceding genera. The lacinia 182-184. is distally beset with small stout spines, Type: Encorethra nnderwoodi Underwood. and the whole lacinia is stoutly sclcrotizccl. 50 The thorax (figure 25A) is more like single, basally serrate, basal process. At that of Moch/onyx than Chaoborus. The the base of the claws there is a pair of anterior pronotal lobes are connected to small, transparent, setaceous pulvilli. :Me­ each other dorsally by a rather large me­ dially between these pulvilli and arising dian sclerite, which is probably homologous from the unguitractor is a branched, seta­ to the median part of the anterior pro­ form cm podium. The halteres (figure 25B) notum in females of M ochlonyx. This me­ are much as in .L11ochlonyx, with a heavily dian sclerite is covered with numerous long setaceous capitulum and with setae on the sctae. This is more or less intermediate be­ anterior and posterior margins of the tween the unseparatcd median lobe of the pedicel. anterior pronotum in females of NI och­ The abdomen of the adult differs but lit­ lonyx and the small detached, scta-bcaring tle from the preceding genera. The spira­ sclerite in Chaoborus. cles are conspicuous between the tergites The posterior pronotum shows a more and sternites, and the chaetotaxy resem­ primitive condition in this genus than in bles that of Mochlonyx. The abdominal any other of the Chaoborinae. The two segments of the male are not as elongate lateral sclerites of the posterior pronotum as in either of the preceding genera, only arc connected by a small band of sclero­ one-tenth longer than broad; segment 8 tization extending across the dorsum be­ is larger, a little more than half as long as t,Yeen the anterior pronotum and the segment 7. mesothoracic scutum. Aside from these few The female genitalia (figure 26A) re­ differences and some differences in propor­ semble those of !Ji ochlonyx cinctipes ,nore tions of parts, the thorax is similar to that nearly than any other member of this of 11l ochlonyx. subfamily. The oviduct opens intc• a The wings (figure 25C) are similar to pocket, the atrium, between segment;; 8 those of the preceding genera except that and 9. This pocket is formed by the i '!­ the forks of RS, M, and Cu are relatively folding of the posterior portion of sternit~ shorter, and An docs not attain the fork 8 so that the duct orifice lies dorsad of of Cu. The membrane is covered with this sclcrite as does the reduced ninth dark microtrichia, and all veins, with the sternite which follows. There are three usual exception of the crossveins and the spermathecae which are spherical in form, distal end of An, have scales. The posterior each with a short, slender neck (figure wing margin bears lanceolate scales as in 26C) . On the apex of segments 10 plus 11 Chaoborus. are the paired, setaceous cerci. The legs are much as in /tf ochlonyx The male genitalia (figures 26B, 26D) except the first tarsal segment is slightly resemble those of wlochlonyx more closely more than twice as long as the second. than those of Chaoborus. This genus differs AL the distal encl of the tibia of each leg from both of the preceding genera in that is a short, stout, rather transparent spur lhe genitalia arc not rotated in any of the (figure 2:3D). There arc at the apex of the specimens seen. The tergite of segment 9 fir:;L, second, third, and fourth tibial joints is produced posteriorly into two spinelike of the prolhoracic, mesothoracic, and processes (figure 26D). At the base of melathoracic legs several short, stout, dark each of these spines is a cluster of about brown to black sctac which might be 18 short setac. The stcrnite of segment Ll'nne(l spurs. Several of these spurs arc 9 is reduced as in the preceding genera. also scaltered along the length of the first The gonocoxites (figure 26B) are simi­ tibial joint of each of the legs. lar to those of the other genera, covered The last tarsal segment is like that in with relatively long and short fine setae. Jloehlonyx; i.e., the males have a proximal There is on the inner face near the apex a lobe and the females do not. The claws cluster of short, stout setae as in Moch­ arc also as in kl ochlonyx except somewhat lonyx. The gonostyle is about one-third stouter. The males have two processes on shorter than the gonocoxite and is beset Pach claw, and the females have but a with short fine setae for its full length. The gonostyle has a short, stout seta at and the distribution of the small dorsal the distal end. setac are the only criteria for distinguish­ The penis valves are large and rounded ing the segmentation of the thorax. Each at the tip. The inner face of each penis abdominal segment bears long lateral and valve is unsclerotized and entirely but short medial setae. sparingly covered with comblike groups Segment 8 (figure 28C) bears the short of very short spines. The actual genital respiratory siphon. When viewed from opening cannot be discerned in any of the above, this siphon resembles the spiracu­ specimens available. lar plate of Anopheles except for the lack The larva of Eucorethra (figure 28A) of a pecten (figure 28B). The spiracular has the appearance of a large anopheline. openings are immediately anterior to the The head is broad, and the antennae are mesa! portions of the lateral flaps. Seg­ widely separated as in M ochlonyx, hut the ment 9 is a small, distinct annulation. siphon (figures 28B, 28C) is very short The anal segment, a composite of the and broad. The ocular-antenna! segment remaining abdominal segments, bears a (figures 27 A, 27B) is large, and the clyp­ dense ventral brush composed of long eus is somewhat smaller, relatively, than in plumose setae as in M ochlonyx. On the M ochlonyx. The antennae are long and dorsal side of the distal end of this seg­ slender and hear at the apex three blade­ ment is a pair of small sclerotized plates, like setae about one-third as long as the each bearing two densely plumose setae. ahtenna. The anal papillae are short and acutely The lahrum (figure 27C) is more obvi­ tapered and lie immediately ventrad of ous from a dorsal view than in the case of the dorsal plumose setae. The anal appa­ MC>chlonyx, hut it hangs down ventrally ratus is a series of stout double hooks and posteriorly so the aboral surface of located on either side below the papillae. the labral apex can only he seen from a The tracheal system is well developed and ventral view. At about the middle of the of the normal culicid form. anteriormost half of the lahrum is located The pupa of Eucorethra is more like a pair of converging linear clusters of flat­ that of M ochlonyx than of Chaoborus. tened, spatulate, and apically toothed se­ The abdominal segments have essentially tae. Laterally, at the distal end of the the same shape as in M ochlonyx, and seg­ labrum are clusters of short spines. Just ment 8 is prominent. Segment 7 is no mesad of these clusters on each side is a larger than the preceding segments. The row of flattened overlapping plates. The tergite of segment 7 (figure 28E) bears homologies of these plates and setae are two stout plumose hairs at each latero­ obscure. posterior corner in addition to a cluster The tentorium is fully developed hut of four plumose setae and one simple seta very delicate and occupies the same posi­ posteriorly on each side of the midline. tion as in ]}f ochlonyx. The anal paddles (figure 28D) are The mandibles (figure 27D) are stoutly slightly variable in shape but usually are sclerotized and have eight teeth, three of ovoid and drawn into a broadly rounded which arc quite small. The mandibles in projection mesally. There is a midrib as this genus lack the fans present in the i11 M ochlonyx and no lateral ribs. The preceding genera and have two sctae at the respiratory horns (figure 28F) are broadly anterior margin. The maxillae (figure 27E) open apically (trumpet-shaped) and thus and labium (figure 27F) are reduced as in differ from both of the preceding genera. the preceding genera and also have spatu­ The actual opening of the trachea seems late and apically serrate setae. to be through a narrow circular aperture The thorax (figure 28A) is somewhat located within the horn. diamond-shaped when viewed from above. From the foregoing it seems evident Laterally there are long, stout tufts of that Rucorethra is, with M ochlonvx, near sctae set in small heavily sclerotize

56 to posterior. The abdomen of the female The antennae are borne on a pair of 1s similar to that of Chaoborus (figure small projections anterior to the clypeus 31B). and posterior to the pendant labrum. The male genitalia (figures 31A, 31C) When at rest the antennae fold back into are rotated through 180° as in the other grooves along the sides of the head. The genera. The gonocoxites are covered with antennae bear three apical bladelike setae, long and short setae, and there is a single, the longest (in C. brakeleyi) about one­ very stout and sometimes quite long seta third of the length of the antenna, the set in a spinelike cup located on the inner shortest about one-third shorter, and one face near the base. The gonostyles are with intermediate. There is also a very short, or without apical armature. curved basal seta. The penis valves are fused distally into The labrum (figure 32C) is ovoid in a single spinelike process but can be iden­ shape transversely and is armed with both tified by their articulations to the gono­ long and short simple setae. On the dorsal coxites and their musculature. The female side distally there are short spines grading genitalia (figure 31B) are practically iden­ into bladelike, trifurcate setae arranged tical with those of Chaoborus except in the in an imbricated fashion. On the oral sur­ matter of setal armature. An additionai face there is a pair of brushes of short, difference is the presence of but a single simple or forked, bladelike setae, depend­ large spermatheca rather than the three ing on the species. The mandibles (figure of the other genera. 32D) are stout, with six or seven teeth, a The larva of C orethrella still retains mandibular fan of seven to nine pectinate some Culicid characteristics but in other blades, and two pairs of stout, flattened respects is as highly modified as Chaobonts setae. The maxillae (figure 32E) and the (figure 33A) . The tracheal system, al­ labium (figure 32F) are much reduced. though reduced, is intact and lacks any The thorax (fig·ure 33A) is broadly oval thoracic or abdominal sacs. The spiracles transversely and bears at the margin long, arc located at the apex of a rather short plumose setae and dorsally small, simple siphon (figures 33A, 33B) somewhat in­ and plumose sctae. The arrangement of termediate in length between that in the setae is all that indicates the segmen­ J1 ochlonyx and that in Eucorethra. tation. Each abdominal segment bears The greatest specializations occur in the long, plumose setae laterally and smaller, !wad (figures 32A, 32B). The head is simple and plumose sctae dorsally. The broad, but the antennae are closely ap­ siphon on segment 8 is short (figure 33B) . proximated. The ocular-antenna! segment The anal segment bears no brush, but this is the largest segment in the head capsule. is represented ventrally by several stout This bears laterally a long row of short, setac. The papillae are short and rounded stout setae as well as several long, simple apically. The anal apparatus consists of .,etac and short, plumose setae. several anteriorly serrate, bladelikc pro­ The clypeus is a conspicuous rectangular cesses-all of which have the same form. plate which is clearly demarked by the The pupa is entirely different from that clypeofrontal suture. The approximation of of any other of the Culicidae. The cephalo­ lhe antennae has isolated the clypeus from thorax is half the total length, and the the labrum; the course of the c!ypeofrontal abdomen is rather sharply tapered. The suture clearly indicates this. The anterior respiratory horn (figures 34C, 34D, 34E) margin of the clypeus bears two pairs of is more or less trumpet-shaped and has a long, simple setac and one medial pair of wide aperture. This is covered by a finely small, plumose setae. The tcntorium is perforated spiraeular end plate. The sur­ slout and well sclerotized, having the same face of the respiratory horn is imbricated position as in the head of the larvae of with very short, broad spines. more or less M ochlonyx. The eyes are reduced to mere scalelike. pigment spots on the outer anterior corners The anal paddles (figures 34A, 34B) are of the head capsule. triangular in shape and fused proximally.

57 They are thick, solid structures with no and abdomen pale grey; medial setae of trace of any supporting ribs. The inner tibiae dark brown to black, remaining se­ margin of the distal end of each paddle is tae and scales brownish; general colora­ serrate. Each paddle is armed with two tion dark brown to nearly black. apical setae, one short and one long, and Head with a long, simple seta medially on the Head capsule dark brown; pedicel light outer margin. Abdominal segment 8 has to dark brown with 20-25 setae; flagellar serrate margins on the latero-posterior segments with long grey setae. Clypcus half and a single pair of setae ventrally. and prcmentum light brown, with very Segment 7 is alrn serrate on the latero­ few light brown setae; maxillary palpi pale posterior margin and bears a few setae, the arrangement of which depends on the grey with sparse pale grey setae; labellae pale grey. Head with a single transverse species. row of short setae across vertex and a rather irregular single row of long setae CORETHRELLA BRAKELEYI around inner margin of eyes. (COQUILLETT} Head width .42-.48 mm.; width between eyes .04 mm.; prementum length .10-.12 Corethra brakeleyi Coquillett, 1902, Ent. mm.; clypeus length .07 mm.; penultimate News 13:85. Smith, 1902, Canad. Ent. antenna! segment length .07 mm.; ulti­ 34:139-140. Dyar, 1902, N. Y. Ent. Soc. mate antenna! segment length .08 mm.; Jour. 10:200-201, pl. 19, fig. 1. Coquil­ H.W./W.B.E. = 10.00-11.33; H.W./P.L. = lett, 1902, N. Y. Ent. Soc. Jour. 10:191- 3.66-t.85; H.W.JC.L. = 6.00-6.80; Pu.L./ 192 (Corethrella). U.L.=.83. Corethrella brakeleyi (Coquillett), Jo­ hannsen, 1903, N. Y. State Mus. Bui. Thorax 68, pp. 399-402, pl. 40. Felt, 1904, Thorax brown to dark brown, pruinose; N. Y. State Mus. Bui. 79, pp. 346- setae of mesoscutum and scutellum dark 347. Dyar and Shannon, 1924, In­ brown. Pronotal setae 5-7; postpronotals secutor Inscitiae Menstruus 12:215- 2-4; upper mesepimerals 12-21; parascu­ 216. Matheson, 1925, Canad. Ent. tellars 1. 57:160. Edwards, 1932, Genera Insec­ Thoracic appendages torum, Fasc. 194, p. 19. :Matheson, 1944, A Handbook of the Mosquitoes of Wing membrane clear or with two North America, Comstock Pub. Co., slightly infuscated bars (figure 30C) . Pat­ tern of wings usually formed by brown Ithaca, N. Y., pp. 91-92, pl. 11, fig. 5. scales on wing veins. \Vhen infuscate

5!) setae proximally and five additional pairs Specimens Examined of simple setae more distally. Oral surface Florida: Lake Worth, Avon Park, Crystal of labrum with messorial brushes of short, River (Citrus County), Miami, West Avo­ flattened, three-tined setae. Mandibular cado, l\farianna Air Base, West Palm fan with seven blades, mandibles with Beach, l\fonticello (larvae, adults); June seven teeth. 7-Dec. IO. Georgia: Okefenokee Swamp; Thorax and abdomen (figures 33A, 33B) June. Louisiana: Baton Rouge, St. Bernard Thorax transversely oval, with long se­ (larvae, adults), Ft. Jackson; Jan. 5-Nov. tae on lateral margins. Lateral setae bi­ 21. Maryland: Plummers Island; Oct. 10. furcate or plumose, set in dark brown, Massachusetts: Belchertown; April-l\1ay l well sclerotized pinnaculae; dorsal setae (larvae). Mississippi: Harmon; May 22. small, simple, and plumose. Abdominal seg­ New Jersey: Lahaway (pupa, adults), ments 1 to 5 with few long lateral sctae Hornerstown; April, J\tlay, November. and with short, simple and plumose setae North Carolina: Jacksonville. South Caro­ dorsally. lina: l\fartsville; June 30. Tennessee: Reel­ Segment 8 (figure 33B) with four pairs foot Lake; Aug. 14. Texas: Conroe, San of lateral setae, the most ventral simple, Antonio, Montgomery County; Aug. 12- the rest bifurcate; an additional small plu­ Sept. 1.5. mose setal pair on posterior margin of dor­ Specimens examined, 122. sal pigment spot. Siphon with a small, plumose seta basally and with two pairs of long, simple setae apically. Anal seg­ CORETHRELLA APPENDI­ ment with anal fan represented by two CULATA GRABHAM pairs of long, simple setae; dorsal brush also represented by two pairs of simple Corethrella appendiculata Grabham, 1906. setae. There are a dorso-lateral pair of Ent. News 17:343. Dyar and Shannon, rather stout setae, a ventro-lateral pair of 1924, lnsecutor Inscitiae l\fonstruus 12: smaller setae, and two pairs of very small 216. Lane, 1942, Rev. Ent. 13:113-115. sctae proximally. Anal apparatus with Lane, 1953, Neotropical Culicidae, Vol. seven or eight anteriorly serrate blades on 1, Sao Paulo, pp. 81-83. each side (figure 33B). Comments PUPA In the material kindly loaned from the Total length (only one specimen) 2.33 collection of Cornell University there is a mm.; cephalothorax slightly more than slide-mounted male and associated larval one-half total length. Color of slide speci­ and pupal skins. This specimen was iden­ men golden brown. Respiratory horn tified as Corethrella appendiculata Grab­ trumpet-shaped (figure 34C), somewhat ham. This specimen fits exactly neither constricted before middle, broadly open the extensive original description nor the apically; covered sparingly with an im­ subsequent one of Dyar and Shannon brication of minute spines; length .27 mm. (1924). However, comparison with spel'i­ Abdomen (figure 34A) sharply con­ mens from Panama, determined by J. stricted between each heavily sclerotized Lane, and comparison \\·ith the cf genitalia segment; each segment somewhat drawn of a cotype of C. appendiculata indicate out at latcro-posterior corners; lateral rows that it is the same species. Discrepancies of spines present; intersegmental mem­ between the original description and the brane with minute spines; median dorsal material examined are: the claws of all setae short. Tergitc 7 without setae at legs are not equal in the male, those latero-posterior corners. Anal paddles bas­ of the prothoracic legs have one larger and ally fused, somewhat irregularly serrate on one smaller than those of the mesothoracic inner margin. Cuticle of whole pupa some­ and metathoracic legs; the basal antenna! what reticulated. segments are darker; and there arc more 60 setae on the head than indicated m any Femora and tibiae light brown with of the descriptions. light brown scales and setae, except at The immature stages of this species apex of each tibia where setae and scales are found in tree holes. dark brown, producing a ringed appear­ ance. Tarsi pale greyish-brown with pale Description setae. Profemur length .60-.61 mm.; pro­ MALE tibia .61-.65 mm.; first protarsus .48-.50 mm.; W.L.jPf.L. 1.92-2.11. Total length 2.37-2.45 mm. Setae of = antennae, maxillary palpi, eighth abdomi­ Abdomen nal segment, gonocoxites, and mesothor­ Ground color of abdomen pale greyish­ acic tarsi pale yellowish; remaining setae brown, covered with long, pale setae. pale greyish-brown. General coloration Genitalia ( figure 31 C) brown as in C. brakeleyi. Segment 8 with setae pale yellow; seg­ llead ment 9 similar to preceding species but Head capsule and pedicel dark grey­ each side of tergite with 25 or more yel­ brown; pedicel with 35 or more setae; lowish setae. Gonocoxites pale yellowish­ flagellar segments pale greyish-yellow. brown, covered with long and short yel­ Maxillary palpi, labrum, and labellae pale lowish setae. Row of five stout setae as yellowish-brown; clypeus and prementum in C. brakeleyi, but very stout seta is pale brown; clypeus with one median seta shorter, not attaining distal encl of gono­ and six or seven lateral setae; head with coxite. numerous short, curved, yellow setae on Gonostyle pale yellowish, slender, as vertex, extending anteriorly between eyes, long as coxite, bearing on inner face proxi­ and a multiple row of long and short setae mally a stout, yellowish seta. Penis valves extending from between eyes over vertex more heavily pigmented than in C. brak­ and along inner margin of eyes posteriorly eleyi, dark brown in color. Coxite length to cephalic margin (figure 31D). .17-.20 mm.; style length .17 mm.; Co.L./ Head width .50-.51 mm.; width between St.L. = 1.00-1.16. eyes .035-.040 mm.; prementum length .11 mm.; clypeus length .07 mm.; penultimate FEMALE antenna! segment length .05-.07 mm.; ulti­ Total length 1.29-1.66 mm. General col­ mate antenna! segment length .07 mm.; oration as in males; setal coloration iden­ H.W.jW.B.E. = 11.66-14.40; H.W./P.L. = tical. U7-4.50; H.W./C.L. = 7.00-7.20; Pu.L./ U.L. = .72-1.00. Head Thorax First antenna! segment with 17-19 long Thorax brown, pruinose. Pronotal se­ setac; peclicel paler than in male, with lae 9-12; posterior pronotals 8-10; upper numerous long setae. Clypeus and premen­ mesepimerals 10-11; parascutellars 1. tum short as in male, with a few more setae (four or five setae on clypeus medi­ Thoracic appendages ally). Wing membrane with two faint brown Head width .55 mm.; width between crossbancls, one from distal encl of Sc to eyes .028 mm.; prementum length .11 mm.; distal encl of Cu , the other one-third dis­ 2 clypeus length .07 mm.; H.W./W.B.E. = tance from wing base and lying between 19.50; H.W./P.L. = 4.87; H.W./C.L. = Costa and M; scales arising from veins in 7.80. areas covered by these bars also grey­ brown, remaining scales pale silvery-grey. Thorax Wing length 1.15-1.30 mm.; wing width Thorax light to dark brown, pale grey .3,t-.37 mm.; W.L./W.W. = 3.37-3.50; around wing bases, pruinose as in C. brak­ W.L./H.W. = 2.31-2.39. eleyi. Halteres with capitulum all brown; pecli­ Pronotal setae 6; postpronotals 10; up­ eel pale, more slender than in C. brakeleyi. per mesepimerals 22; parascutellars 1. 61 Thoracic appendages opening large, located at external opening Wings marked and colored as in males. of trumpet. Surface of horn imbricated Wing length 1.24-1.48 mm.; wing width .38 with short, wide spines like reptile scales; mm.; W.L./W.W. = 3.22; W.L./H.W. = total length .21 mm. Abdomen (figure 2.23. Claws all of equal size, small as in 34B) sharply constricted between each mesothoracic and metathoracie legs of heavily sclerotized segment; each segment males. Profemur length .G2 mm.; protibia drawn out into spines at latcro-posterior .GO mm.; first protarsus .45 mm.; W.L.j corners. Setae dorsally as in illustration; Pf.L. = 1.97. segment 7 with one seta at each latero­ posterior corner. ,vhole surface of cuticle Abdomen more or less reticulated. Morphologically as in females of C. brakclcyi. Spermatheca somewhat ovoid in Specimens Examined shape, .05-.0G 111111. in diameter. Georgia: l J, 1 larval and 1 pupal skin, Macon (hole in gum log); October 19H LARVA (slide mount). Jamaica: l J, Kingston; Total length of larval skin (stretched) June 17, 190G; 1 J, genitalia of cotype, 2.G0 mm. Nearly colorless, with pale yel­ Kingston. Panama: 5 JJ, 3 'i''i', Tabernilla, lowish-brown head; mandibular teeth C. Z., A. Busck (Det. J. Lane, 1941); 4 black; spines at anterior edge of submen­ des, 3 'i''i', Gatun, C. Z., 192G, D. P. Curry; tum dark brown; margin of foramen mag­ 2 &s, 1 'i', Gatun, C. Z., September 15, num dark brown; siphon and anal seg­ 192G, D. P. Curry. St. Domingo: 1 J, San ment pale yellowish-brown; all body setae Francisco Mountains, September 190/i. black. Total specimens examined, 24. Head Head length .35 mm.; head width .Gl CORETHRELLA LANEANA mm.; antenna length .15 mm.; length of longest antenna! seta .08 111111.; length of VARGAS intermediate seta .05 mm.; length of short­ Corethrella laneana Vargas, 194G, Rev. est seta .0-t mm. Head essentially as in Inst. de salubr. y Enferm. trap. lVIcxicn C. bralceleyi except setae of clypeus all 7:57-62. Belkin and McDonald, 1955. simple as are those of ocular-antenna! seg­ South. Calif. Acad. Sci. Bui. 54:82-96. ment; sutures bounding submentum paral­ lel rather than divergent (figure 33C), Comments apex of labrum with messores made up of simple rather than forked setae (figure This species was originally describecl 33D). Mandibles with six teeth; mandibu­ from a single male specimen collected in lar fan of nine bladelike, pcetinate setae. June l9-t4 in _Monterrey, Nucvo Leon. l\iexico. It was not recorded again until Thorax and abdomen 1955 when Belkin and McDonald reported Actual groupings of thoracic and ab­ on their collection of adults and larvae at dominal setae cannot be ascertained from Saratoga Springs in Death Valley, Cali­ this cast skin, although arrangement is fornia in I 9,3,t. similar to that in larva of C. bralceleyi. The holotypc of Vargas' species has not Xo conspicuous brown spots on abdominal !wen seen, but comparisons can be made segments. Siphon and anal segments simi­ with photographs in Vargas' paper. Bel­ lar except basal seta of siphon is simple. kin and McDonald believe that the Death Valley specimens may be distinct enough PUPA (figures 34B, 34-D) from the Vargas-described specimen lo Total length 2.88 mm.; ccphalothorax constitute a distinct subspecies. They clo one-half total length; pale yellow-brown not, however, so name it. Dr. Belkin has (cast skin); respiratory horn (figure 34D) very kindly permitted the author to ex­ somewhat trumpet-shaped, spiracular amine adults, pupae, and larvae from his

62 collection. These specimens are here con­ Thorax sidered to be conspecific with Vargas' spe­ Thorax greyish-brown, pruinose; setae cies. of mesoscutum and seutellum long and In the males, C. laneana is readily dis­ dark with an admixture of small, fine, tinguished from C. bralceleyi and C. ap­ pale setae. Pronotal setae, 2 large and 2 pendiculata by the presence of a conspicu­ small; postpronotals, 2 large and 1 small; ous apical seta on the gonostyle (figure upper mesepimerals 0-2; parascutellars 1. 31E). In both males and females it can he distinguished from C. bralceleyi by the Thoracic appendages numerous setae on the clypeus (C. bralc­ Wing membrane clear except for slight elcyi with only 5 or 6, C. laneana with darkening between R 1 and Sc; pattern of 20-30) . wings essentially as in C. bralceleyi (figure The larvae are indistinguishable from 30C), also formed by dark scales on wing those of C. bralceleyi except in C. bralceleyi veins. ,ving scales otherwise silvery-grey the anal and dorsal brushes are each com­ except dark scales at apex of wing and on posed of four single setae. In C. laneana wing margin between Cu1 and Cu~. Pos­ these setae are bifid. The reliability of this terior marginal scales present, identical character is an open question. with those of C. bralceleyi. Wing length The pupae of C. laneana differ from C. 1.08 mm. (not including fringe); wing bralceleyi in that the respiratory horn of width .31 mm.; W.L./W.W. = 3.47; W.L./ the former shows no trace of a medial con­ H.\V. = 2.63. striction (figure 3.J.E). Halteres pale grey; apex of capitulum pale brown. Description Femora and tibiae pale brown, very light distally, somewhat darker basally; l\fALE tarsi all pale grey. Legs covered with long Total length 1.70 mm. Setae colored and short setae; claws pale, simple, those as in C. brakeleyi; general coloration pale of prothoracic legs unequal and larger greyish-brown. than those of other legs. Length of pro­ Head femur .51 mm.; protibia .51 111111.; first Head capsule light grey-brown; pedicel protarsus .46 111111.; W.L./Pf.L. = 2.34. darker grey-brown with approximately 20 Abdomen sctae; antenna! segment 1 (scape) with Ground color of abdomen pale grey­ three conspicuous setae laterally; flagellar brown· abdomen covered with long and segments with long grey selae, darker at short 'pale setae. Tergites and sternites whorl. Clypcus and prementum light grey­ equally developed and pigmented. Spira­ brown; clypcus with about 22 sctae, pre­ cles small, inC'onspicuous. mentum with about 30 setae; labellae pale grey. Head with a small number of Genitalia ( figure 31 E) short, proclinate setae across vertex and a Seo-rnent 8 setaceous dorsally and ven­ single, rather irregular row of long setae trall:t Tcrgite 9 bilobecl, eacl; lobe with around inner margin of eyes from above 15 long setae; median membranous area antennae to ventral margin of head pos­ not markedly acute; sternite 9 reduced. teriorly. Gonocoxite pale brown; a row of five long Head width Al mm.; width between setae on inner face of dorsal side; stout c·yes .OG mm. (somewhat wider than in C. seta near proximal encl of row is set in lirakc/cyi); prementum length .12 111111.; cuplike base. This seta is much shorter el)·peus length .08 111111.; penultimate an­ than in C. brakelcyi (about one-third the lPnnal segment length .07 mm.; ultimate length of gonocoxite). Gonostyle (figure antenna! segment length .07 mm.; H.W.j 3IE) stouter than in C. brakeleyi, ex­ W.B.E. = 6.8; H.W.jC.L. = 5.1; Pu.L./ panded distally and bearing a small apical ll.L. = 1.00; H.W./P.L. = 3.4. seta in addition to one stout seta one-third

63 distance from base and an additional stout Abdornen seta one-eighth distance from base. Gono­ Abdomen and genitalia as in C. bralc­ style pale, transparent. Penis valves as in eleyi. Spermatheca .069 mm. in diameter. C. brakeleyi. Coxite length .17 mm.; gono­ style length .12 mm.; Co.L.jSt.L. = 1.41. LARVA Total length (slide specimen) 3.50 mm.; FEMALE apparently colored as C. bralceleyi with Total length 1.82-1.90 mm. Somewhat identical spots and pigment patches. darker and with more marked wing pat­ Head tern than male. Seta color largely as in Head length .51 mm.; head width .76 male. mm.; antenna length .24 mm.; length of Head longest antenna! seta .13 mm.; length of Head capsule brown; first antenna! seg­ intermediate seta .10 mm.; length of short­ ment with 13-15 setae; pedicel dark brown est seta .07 mm. with numerous short, brown setae. Setae Chaetotaxy and appendages identical at flagellar whorls and those between with C. bralceleyi. Mandibular fan with shorter than in male. C!ypeus and pre­ seven blades; mandibles with nine teeth. mentum brown, setae brown, numerous Thorax and abdomen (30 or more); maxillary palpi and labellae Chaetotaxy and structure identical with pale grey with like-colored setae. Head C. brakeleyi except anal fan and dorsal with few short, proclinate setae and a few brush are represented by two pairs of long somewhat longer straight setae over ver­ bifid setae. Anal apparatus as in C. bralc­ tex in addition to the single row of very eleyi. long setae reaching from anterior aspect between eyes, over vertex, to ventral mar­ PUPA gin of head posteriorly. Total length approximately 2.40 mm.; Head width .45 mm.; width between cephalothorax somewhat more than one­ eyes .05 mm.; prementum length .13 mm.; half total length; yellowish-brown. Respira­ clypeus length .10 mm.; H.W./W.B.E. = tory horn .34 mm. long, trumpet-shaped, 9.00; H.W./P.L. = 3.46; H.W./C.L. = not particularly constricted medially (fig­ 4.50. ure 34E); no spinelike imbrications ap­ Thorax parent on available specimens. Thorax brown, somewhat darker than Abdomen anatomicallv like C. brak­ in male. Pronotal setae, 2 large, 8 small; eleyi. Tergite 7 with a sm~ll seta near each posterior pronotals, 2 large, 1 or 2 small; postero-lateral corner and two pairs of upper mesepimerals 4. small setae between margin and stout, me­ dian pair; otherwise as in C. bralceleyi. In Thoracic appendages the two specimens available there appears Wing pattern as in males. Wing length to be a ribbed membrane along the margin 1.30-1.38 mm. (less fringe); wing width of segments 2-7. This was apparently il­ .41 mm.; W.L./W.W. = 3.17-3.39; W.L./ lustrated by Johannsen for C. brakeleyi H.W. =3.06. but was not apparent on the specimen of Femora and tibiae brown; femora pale that species available to the author. at distal ends; tibiae dark at distal and proximal ends; tarsi light grey. Legs cov­ Specimens Examined ered with long and short setae, longest on profemora and metatibiae; setae less well California: Saratoga Springs, Death Val­ developed than in male. Length of profe­ ley; 1 r! genitalia, 2 ~~. July 28, 1954; 1 o, mur .62 mm.; protibia .62 mm.; first pro­ Sept. 10-11, 1954; 1 larva, Sept. 10, 1954; tarsus .48-.52 mm.; W.L/Pf.L. = 2.65- 1 pupa, July 28, 1954; 1 larval and 1 pupal 2.70. skin, Sept. 10-ll, 1954.

64 ,c~O,NTAL MACL.JLA .,.....- OCULAR-ANTENNAL SEGMENT POSTGENAL BRIDGE ___ __.. _CORONAL STRIPE / ' ' ' ' ' FORAMEN MAGNUM - __ - -ANTENNAL FORAMEN -- _____ -EYE- __ ---

____ -ANTERIOR TENTORIAL PtT

--MANDIBLE -MAXILLARY PALPUS- PREMENTUM- -- -- ___ -LABRUM ------LABIAL PALPUS __ I I I C, I '" I I l I / I / '-. / " I / '-. \ \ / '-. / " / '-. OCULAR FORAMEN/--- " 'TENTORIUM CLYPEUS------PREMENTUM J»

A. CEPHALIC ASPECT B. LATERAL ASPECT C. CAUDAL ASPECT

Fig. 1. Chooborus omericanus-heod of adult female. -- -CARDO

/ CEPHALIC CAUDAL

B. HEAD OF d'"

_,,. PALPUS

LACINIA \ CLYPEUS ABORAL ORAL

A. MAXILLA C. MANDIBLE D. LABRUM

Fig. 2. C. americanus-details of head and mouthports. -CIBARJUM ------CLY PE US-. ------.. .._-... ------.. -.. -... ------MANDIBULAR ARTICULATIONS.___.__ ...... ---- ...... ---

MEDIAN LOBE.____ --··PREMENTUM

----­ ', '

LABIAL PALPUS -- -

C. LATERAL VIEW OF ROSTRUM, A. MANDIBLES Si Cl BARIUM 8. PREMENTUM Si LABIALPALPI PREMENTUM REMOVED

Fig. 3. C. americanus-details of mouthparts. scyTUM POSTERIOR ANEPISTERNUM 2 ANTERIOR ANEPISTERNUM 2 I I / PLEURAL WING PROCESS SPIRACLE I I PARASCUTELLUM I EPIMERON I I I ;WING BASE \ I I I / POSTERIOR PRONOTUM I \ \ I I I I / PLEURAL CLEFT 2 \ / \ I I / _.,.SCUTELLUM \ I I ' I / / ___.--;LATEROTERGITE ' ~- / ANTERIOR PRONOTUM ' / ___.- ___.- / / /SPIRACLE 2 \ ' I ,-;. _.,. // / \ 0 0 ' ,:- 0 • / / / / _.,. _.f>OSTNOTUM ANEPISTERNUM I'­ \ HALTERE BASE '- / ./ .,,. _.,.-=-- ::---~-==- _.METANOTAL- PROCESS _.,. __ - -METANOTUM

PLEURAL SUTURE 2- - ___ - - -PLEURAL SUTURE 3 PLEURAL APOPHYSIS- _-_-_- \­ PLEURAL SUTURE 1- - __ ------3 LATERAL COXAL CONOYLE ' 'sASALAR SCLE~E -- -- - EPIMERON '-.'- ...__',PLEURAL CLEFT -ANEPISTERNUM 3

PREEPISTERNUM 2 - .____ '-. '-'KATEPISTERNUM 3 _.,. '--...__ '- ANEPIMERON 2 COXA, ..- ---­ / / 'MERON KATEPIMERON 2/ COXAZ/ ---coxA 3 A. LATERAL VIEW

KATEPIMERON LATERAL COXAL ARTICULATION PREEPISTERNUM \ KATEPISTERNUM 2 /KATEPISTERNUM 3 \ I / / STERNUM 2 / KATEPISTERNUM I \ I I I \ ;~MEDIAN COXAL ARTICULATION \ I I / \ \ \ I I / / /OISCRIMINAL LINE \ ___ _ I ANTERIOR PRONOTUM I I // /' I \ I / /~/ ////STERNALAPOPHYSIS3 I I / / / //

--- - COXALCAVITY

OISCRIMINAL LINE

/ ---- '-- COXALCAVITY/ // ---- 'MEDIAN COX AL ARTICULATION

STERNUM I/ / / MERON PLEURAL CLEFT STERNAL APOPHYSIS 2 COX AL CAVITY 8. VENTRAL VIEW

Fig. 4. C. omericonus-thorox.

68 PLEURAL WING PROCESS POSTERIOR PRONOTUM EPl~.-!ERON 1 SPIRACLE SCUTUM PREALAR APOPHYSIS \ \ I I I / \ \ I / I I \ \ / , SCUTELLUM PLEURAL CLEFT I / \ \ I I / / \ \ I I / ' \ / / ~ \ \ I I I / / \ \ / /POSTNOTUM ' ~ I / / \ / / ANTERIOR PRONOTUM '\ / / \ \ \ / / \ '\ \ / \ \ / /METANOTUM ~ \ / \ / / / \ / \ / ANEPISTERNUM 1, / - PLEURAL SUTURE 2 '--- ' '--- '--- ' ' ------SPIRACLE

PLEURAL SUTURE 1- _ '--._ ------PLEURAL SUTURE 3 -- '--._ '--._ '--._

"--- '--._ ,,,, '--- '--._ ANEPISTERNUM 3 ,,,, ----­ "--­ '------"--- LATERAL COXAL ARTICULATION,,------1/ '--- ,/ / '--._ ,,,, ,./ '--- STERNAL APOPHYSIS 3 ,./ / \ "--- / / "--- /' \ \ / / "--- KATEPISTERNUM I,,- / / / \ \ ~ATERALCOXALARTICULATION2 / / "\ ,,, / / I '\ PREEPISTERNUM2 /PLEURAL APOPHYSIS 2· KATEPISTERNUM 2 STERNAL APOPHYSEAL PIT MEDIAN COXAL ARTICULATION

Fig. 5. C. americanus-internal aspect af thorax. ANTERIOR PRONOTAL SETAE POSTERIOR PRONOTAL SETAE /PARASCUTELLAR SETAE \ '\ / '\ MEDIAL PRONOTAL SETAE -- -....._ '\ '\ -ANEPISTERNAL SETAE

ANTERIOR PRONOTUM - -

-- SUBALAR PROCESS / /, '-----UPPER MESEPIMERAL SETAE / / / / "'- EPISTERNAL SETAE B. CEPHALIC VIEW ""'- PREEPISTERNAL SETAE _, 0 A. LATERAL VIEW

ANTERIOR PRONOTUM SCUTUM SCUTELLUM \ I \ \ I PLEURAL APOPHYSIS- \

- - - POSTNOTUM

_,/° STERNAL APOPHYSIS .-/°

D. MESOTHORACIC STERNAL C. DORSAL VIEW APOPHYSIS, CEPHALIC VIEW Fig. 6. C. americanus-details of thorax. ____ _.....COXA'--"--.'--.if:·.: ((·;? ------___...TROCHANTER •••J ~

MESAL VIEW

-FEMUR TARSUS-

LATERAL VIEW

A. PROTHORACIC LEG

-TROCHANTER

LATERAL VIEW LATERAL VIEW B. MESOTHORACIC COXA C. METATHORACIC COXA

DORSAL

POSTERIOR

D. CERVICAL SCLERITE E. CLAWS S. PULVILLI

Fig. 7. C. americanus-detoils of legs.

71 1ST. AXILLARY SCLERITE --- HUMERAL PLATE \ COSTA------= ------__....ANTERIOR NOTAL PROCESS

/ /f'ARASCUTELLAR SETAE SUBCOSTA/ / /

RADIUS/

..____ '-SCUTELLUM '--­ \ '----- '------..__ '--- \ "PosTERIOR NOTAL PROCESS

\ ------'---. \3RD. AXILLARY SCLERITE 'AXILLARY CORD MEDIAN PLATE/ A. DORSAL VIEW

2ND. AXILLARY SCLERITE ANEPISTERNUM"' PLEURAL WING PROCESS \ "'-, \ I I I I I I

EPIMERON.---

/ / ...._...._ --..______POSTERIOR NOTAL PROCESS BASALAR SCLERITE/ B. LATERAL VIEW

Fig. 8. C. americanus-wing bases.

72 CAPITULUM ------2NO.AXILLARY SCLERITE

I /I ST AXILLARY SCLERITE TEGULA I \ I // \ \

/METANOTUM

PENIS VALVE-

GONOCOXITE---

-.....___ SUBALAR PROCESS ,.._____

"-PLEURAL WING PROCESS

SPIRACLE A. HALTERE ANUS PENIS VALVE C SC RI GONOGOXITE"'

~'~:~,

GU2 TERGITE 9 C. WING D. MALE GENITALIA

Fig. 9. C. americanus-haltere, wing, and male genitalia. STERNITE \ --SPERMATHEGA \

ANTERIOR

GONOPORE ,------SPERMATHEGAL DUCT

STERNITE 9

SEGMENT IQ-

-STERNITES A. GENITALIA' VEN TRAL ASPECT -TERGITES

TERGITE 8

C. LATERAL ASPECT

STERNITE

D. ABDOMINAL SEGMENT 3

8. DORSAL ASPECT

Fig. l 0. C. omer,canus. -female genitalia. . an d abdominal segment 3. ,..,,.-CORONAL SUTUA ... SUBMENTUM / I / MAXILLA...._ / / ------...... / ~OCULAR-ANTENNAL SEGMENT---::::----

/ / / / ------LARVAL EYE ------...._

/ / / / ------ADULT EYE ------'------. / ------MAXILLARY PALPUS...... _ --.._____

/ ------MANDIBLE- ...... _ ...____-..._ ---- _,,,,,,,------__,.... ------__,.... LABRUM -...__ -- ---..._ ------//~~ -~~~~~~-

__.... ------­ POSTERIOR TENTORIAL PIT__.... '""'- ANTENNAL'"' FORA~A

-·MAXILLA LARVALEYE------~------.=--LABRAL BRUSHES (MESSORIAL BRUSHES) ADULT EYE..------MANDIBLE- -- __ - - PRELABRAL APPENDAGES

------POSTANTENNAL FILAMENTS ANTERIOR TENTORIAL PIT------~~--====~~~ ------ANTENNA A. DORSAL ASPECT B. LATERAL ASPECT C. VENTRAL ASPECT

Fig. 11. C. americanus-head of larva. A. SIDE VIEW OF LARVA

SUBMENTUM/ "/·s... . \ PREMENTUM --- LABIAL PALPus- --STIPES/"""'"' ~. i/- SALIVARY DU CT - -- d 11 C.MAXILLA i/\1:mmi B. LABIUM D. PRELABRAL APPENDAGE _.,.,--SEGMENT 9 ANAL GILLS 11 /_ I I I I E. MANDIBLE I

F. ANAL SEGMENT

H. ANAL PROCESSES G. VENTRAL HOOK

Fig. 12. C. americanus-details of larva.

76 ---'--~_,*,,.· ~

E. C. ASTICTOPUS cf

·,··80' ~--·.,,·,,= ', F.CALBATUSrf ' .::: .. ::: '':·-~ ~ ' ;:~;, -~.:.":~_:: .:. : : .. ~ G.o,,,,," e ~~ H. C. ANNULATUS 'r

Fig. 13. Chaoborus spp.-thoraces and wings.

77 0 0

A. C.AMERICANUS 8. C.FLAVICANS C. C. BOREALIS 0. C. NYBLAEI

H. C. AMERICANUS 0

i,C.FLAVICANS E. C.PUNGTIPENNISVO F. C.ASTICTOPUS G. C. ALB AT US J. C.NYBLAEI C. PUNG TIPEN NIS K. L. C. ASTICTOPUS 0 OC>O M. C. BOREALIS (MINN.I N. C.ALBATUS (LA.) 0, C.ANNULATUS

Fig. 14. Chaoborus spp.-pattern of abdominal terga 3 and 4 of males and spermathecae of females.

78 STERNITE 8\------~----- /ERGITES

VENTRAL DORSAL A. CHAOBORUS NYBLAEI

,.,.-STERNITES

,,/' TERGITE 8------STERNITE9 '------

1'/ TERGITE9~ ~

----SEGMENT ID-

VENTRAL DORSAL 8. CHAOBORUS PUNCTIPENNIS

Fig. 15. Female genitalia of subgenera Schadonophasma and Soyomyia.

79 B. PENIS VALVE D.

G. PENIS VALVE OF H. VARIATIONOF C OF IN PENIS VALVES C. AMERICANUS • FLAVICANS

I I/ l >--- __ _j / E. C.ASTICTOPUS

..1\ /}{

F, VARIATION IN PENIS VALVE OF C.ASTICTOPUS 5

Fig. 16. Chaoborus spp.-male genitalia.

80 F.c. PUNCTIPENNISfl G. C. NYBLAE I

A. C. FL AV I CANS

C. C. PUNCTIPENNIS D. C. ASTICTOPUS E.C.ALBATUS

H.C FLAVICANS I. C. AMERICANUS PRELABRAL APPENDAGES MANDIBULAR TEETH

P.c ASTICTOPUS

M.C. PUNCTIPENNIS N.c. ASTICTOPUS 0. C ALBATUS LABRUM

J, C. NYBLAEI K.C.AMERICANUS L. C.FLAVICANS ANTENNAE

Fig. 17. Chaoborus spp.-larval structures. LATERAL RIB MESAL RIB / " / ""' /

C. AMERICANUS, ANAL PADDLE C. FLAVICANS OF PUPA D. G. C.NYBLAEI

~

8. C AMERICANUS, 7TH. ABDOMINAL E. C FLAVICANS ~ SEGMENT OF PUPA \) H. C. PUNCTIPENNIS C.C. AMERICANUS, RESPIRATORY HORN OF PUPA

F. C. NYBLAEI I. C. PUNCTIPENNIS

_ -DORSAL PROCESS 9TH.SEGMENT------

/

8TH. SEGMENT/

J. C. ASTICTOPUS, CAUDAL SEGMENTS OF LARVA K. C. ASTICTOPUS·-

Fig. 18. Chaoborus spp.-larval and pupal structures.

82 --CARDO

C.MANDIBLE / / / / ---STIPES GLYPEUS ---LABRUM

"-.._PREMENTUM

CEPHALIC ASPECT CAUDAL ASPECT

A. HEAD OF FEMALE

/TENTORIUM /

D.LABRUM E. MAXILLA

Fig. 19. Moch/onyx ve/utinus-head and mouthparts of adult. ANTERIOR PRONOTUM SCUTELLUM \ I \ \ I \ I -SEGMENT I

-SEGMENT 2

ATEPISTERNUM 3 00 ( ... B. 1ST. 8i 2ND. TARSAL \ PREEPISTERNUM 2/ SEGMENTS !j! \ MESAL ASPECT \ PLEURAL APOPHYSEAL PIT LATERAL ASPECT C. HALTERE i A.~ THORAX

EMPOOIUM \ \ \ ~

-- - - -uNGUITRACTOR

D. CLAWS cf

Fi . 20. Mochlon x ve/utinus-thorax and a enda es. TERGITE 8 GONOSTYLE ' \ " "' \

D. A. M,VELUTINUS d GENITALIA E. M,GINGTIPES,d', TERGITE 9

GONOCOX1TE-- --

~~ =>ENIS VALVE - 8, M. VELUTINUS, d'GENITALIA F. M. GINGTIPES, PENIS VALVE G. M.GINCTIPES, GONOSTYI..E

Fig. 21. Moch/onyx velutinus and M. cincfipes-genitalia. __,.POSTERIORTENTORIAL PIT / _,,DCULAR-ANTENNAL SEGMENT / /1/ _.....--LARVALEYE--

_,,.ADULT EYE-_ / MAXILLA-­ MANDIBLE-- -

...... ANTENNA.._ ,,,..-.,...... ----- ,,.- ,,.------\ANTERIOR TENTORIAL PIT

00 Cl

E.MANDIBLE F. LABIUM

Fig. 22. M. ve/utinus-larval head and mouthparts. SIPHON / /

/CLYPEUS A. LARVA

-LABRUM

POSTERIOR A~~~cOJ~~i'°I~%/ • B. LARVALHEAD,ANTERIOR ASPECT PUPAL RESPIRATORY HORN

PENIS VALVE rf' TERGITE 8 C. PUPAL PARTS GONOCOXITE BASE D. M.FULIGINOSUS, d'GENITALIA

Fig. 23. M. ve/utinus-pupal and larval parts; M. fuliginosus-male genitalia. O~LAR-ANTENNAL SEGMENT ANTENNAL SEGMENT I PARAGLYPEAL LOBE /CARDO POSTERIOR TENTORIAL PIT / I / I "' / I "" I,

C.MANDIBLE

\ \ MAXILLARY PALPUS---..

LAGINIA-

D. MAXILLA

Fig. 24. Eucorethra underwoodi-head and mouthparts of female. METAN01:,!:!M / /

ANEPISTERNUM 1---

--EPIMERON 2

p REEPISTERNUM 2 --­

PLEURAL SUTURE 2/

MESALASPECT LATERAL ASPECT A.THORAX d B.HALTERE

TARSUS '\ \

------­TIBIA

C. WING /J D. MESOTIBIAL SPUR

Fig. 25. E. un d erwo odi-thorax and appendages. TERGITES-­

~ STERNITE 8 / / .-·.·:.·_.· .. )'.1 r ·-- -- TERGITE 9------

VENTRAL ASPECT DORSAL ASPECT A. FEMALE GENITALIA d

C. SPERMATHECA

VENTRAL ASPECT DORSAL ASPECT D. MALE TERGITE 9

8. MALE GENITALIA

Fig. 26. E. underwoodi-male and female genitalia.

90 LABIUM POSTERIOR TENTOR!AL PIT..____ /' OCULAR-ANTENNAL SEGMENT ------­ ' _,.....- _..,-- ___....CORONAL SUTURE /""' _..,..- SUBMENTUM ____

___...... --LARVAL EYE...___...___

..-ADULT EYE----­ ___...... -- MAXILLARY SEGMENT-----

- -CLYPEUS

MAXILLA-- __ -+"'l!k:ioc_::S,~!,I~ MANDIBLE- __

_ -LABRUM

..-ANTENNA-­ \ --- \ \ A. CEPHALIC ASPECT B. CAUDAL ASPECT \ POSTERIOR MANDIBULAR ~ ARTICULATION ~~ ~AXILLARY PALPUS E. MAXILLA

D.MANDIBLE

F. LABIUM

Fig. 27. E. underwoodi-larval head and mouthparts. LATERAL FLAP SPIRACLE SIPHON / / ""'

POSTERIOR PLATE/ I I B. SPIRACULAR DISC SIP/' I DORSAL BRUSH\ ,/ / /\I

D. PUPAL ANAL PADDLE

E. PUPAL TERGITE 7

Fig. 28. E. underwoodi-larval and pupal parts. ----co:1c.,1u1.L SIJTURE

--- -EYE------

------ANTENNAL SEGMENT------I ------/ANTERIOR- TENTORIAL PIT / POSTERIOR TENTORIAL PIT---....___

------_.-CLYPEUS --- STIPES- ---- _.-MAXILLARY PALPUS------LACI NIA------PREMENTUM---=------===---- ~----______- -MANDIBLE ------LABIAL PALPUS ANTERIOR TENTO~L PIT B. CAUDAL ASPECT

A. CEPHALIC ASPECT

D. MANDIBLE F. C, Tl BIAL SPUR C. ~ TIBIAL SPUR

Fig. 29. Corethrella brakeleyi-head and mouthparts of male, tibial spurs. /SCUTUM

/SCUTELLUM '---.., / /CAPITULUM _,-, POSTNOTUM ---- ~METANOTUM

",/" PEDICEL ------KATEPISTERNUM 3 /

LATERAL ASPECT MESAL ASPECT A. MALE THORAX B. MALE HALTERE

D. MALE MESOTHORACIC CLAWS

C.MALE WING E. MALE PROTHORACIC CLAWS

Fig. 30. C. brake/eyi-thorax and appendages. ____ -GONOGOXITE...... ______

--PENIS VALVES--

I ------~~:,; ~J :i ' .~ j ;·/ ~'- ( C C.APPENDICULATA d' GENITALIA STERNITE --'-- TERGITE 9 9-'.,...:::..::.----­ 1 \ '------J A. C. BRAKELEYI,

E. C.LANEANA, D. C. APPENDICULATA, GONOSTYLE OCCIPUT

Fig. 31. C. brakeleyi-genitalia; C. /aneana-gonostyle; C. appendiculata-male genitalia, occiput. MAXILLA

__ ~ANTENNA

A. CEPHALIC ASPECT

E. MAXILLA

D. MANDIBLE

F. LABIUM

Fig. 32. C. brake/eyi-larval head and mouthp · r:s. SIPHON

-----..._ANAL APPARATUS

B. TERMINAL SEGMENTS

MESSORES--

C C APPENOICULATA D LABRAL APEX LARVAL SUBMENTUM

Fig. 33. C. brake/eyi-larva and details; C. appendicu/ata-details of larva.

97 B. C APPENDICULATA, ABDOMEN A. C.BRAKELEYI, ABDOMEN

. E. C. LANEANA, RESPIRATORY HORN

C C. BRAKELEYI, RESPIRATORY HORN D. C APPENDICULATA, RESPIRATORY HORN

Fig. 34. C. brakeleyi, C. laneana, and C. appendiculata-pupal parts.

98 LITERATURE CITED

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102