Copyright © 1983 Ohio Acad. Sci. OO3O-O95O/83/OOO3-OO74 $5.00/0

A REVIEW OF THE IN OHIO, WITH A KEY TO ADULTS OF SPECIES OF THE NORTHEASTERN UNITED STATES (DIPTERA, )1

M. W. BOESEL, Zoology Department, Miami University, Oxford, OH 45056

ABSTRACT. In the northeastern states, 21 species of Cricotopus are recognized: C. syl- vestris, uncommon in Ohio but abundant in California, the larvae feeding on rice plants, Spirogyra, Myrioph yllum and other vegetation; C. trifasciatus ( — remus), with larvae mining in and skeletonizing leaves of Potamogeton, Polygonum, Nuphar, Nymphaea and Nelumbo; C. bkinctus, living as larvae in masses of Spirogyra, capable of withstanding low oxygen levels and showing remarkable resistance to pollution by industrial wastes; C. tricinctus ( = lebetis), more or less questionably distinct from C. trifasciatus; C. triannulatus { — exilis), a northern Holarctic species associated with swift streams or shallow areas of lakes subject to wave action; C. politus, a clean-water species of lakes and streams; C. varipes and C. slos- sonae, closely related species showing a positive response to crude oil contamination; C. absurdus, with Neotropical affinities and apparently rare in the northern Nearctic; C. fugax, not recorded since it was described; C. flavibasis, closely related to C. sylvestris; C. infuscatus {=aratus, ceris), with larvae showing considerable resistance to heavy-metal pollution; C. vierriensis, easily confused with C. bicinctus, with larvae able to withstand high salt concentrations; C. trifascia ( = ithacanensis), having larvae present in small num- bers in streams; C. flavipes, relatively rare, the larvae making linear mines in submerged leaves of Potamogeton; C. elegans, rarely reported, with larvae riddling the floating leaves of Potamogeton; C. junus, with larvae inhabiting hard-bottom creeks; and C. nostocicola, with larvae feeding on Nostoc and attaching the algal colonies to rocks and other objects. New species are C. diversus, with similar to C. junus except for leg coloration and to the European C. festivellus except for details of abdominal coloration; C. baptistenis, known only from southern Canada but at the latitude of Michigan; and C. olivetus, probably most closely related to C. fugax and the European C. annulator.

OHIO J. SCI. 83 (3): 74-90, 1983

INTRODUCTION present paper is an attempt to summarize The genus Crkotopus is of particular im- information available for species of north- portance in stream ecology. In a recent eastern United States and to provide a key study of a small limestone stream subjected facilitating determination of adults. So far to heavy-metal pollution, the relative as possible both dry and slide-mounted in- abundance of the genus proved to be dividuals have been studied. Dry speci- ecologically significant. In the area of mens reveal tralts such as wing reflections heaviest pollution, Cricotopus larvae made and surface texture but slide-mounted ma- up about 90% of the chironomid popula- tenal 1S hlBh[Y desirable for microscopic tion; at about 3.4 km downstream they details- Qmte certainly specimens will be constituted only about 20% of that popula- found which wl11 not flt mt0 any key, for tion (Winner et al 1980). Furthermore, aberrant individuals are not uncommon, species within the genus exhibit a wide No current study of Cr/r^^ can ignore range of environmental demands. The the monumental work of Hirvenoja (1973). He noted that color variation occurs widely 'Manuscript received 26 April 1982 and m re- m Crkotopus. In some species he recognized vised form 20 August 1982 (#82-10). and figured normal, dark and light forms 74 OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 75 where in fact all gradations of color occur. ated with the genus. Species with strong, He also noted considerable variation in erect hairs with distinct bristle punctures size. Color in some chironomids is known were placed in Trichocladius, which was to vary with degree of maturity (Boesel commonly regarded as a subgenus of 1974). As indicated by Johannsen (1905), or Spaniotoma or given generic in making determinations in Cricotopus it is rank. The present paper adopts a broad extremely important to note that in mela- concept for Cricotopus but excludes the spe- nistic specimens areas of the abdomen that cies which have traditionally been assigned are normally yellow-white tend to be to Trichocladius and sometimes referred to black. However when such specimens are , or Paratricho- examined at an appropriate angle, surfaces cladius. Included, however, are species which are typically or commonly yellow- sometimes listed under Isocladius and white are shining whereas those that are . Hirvenoja (1973) treated all of black are velvety or dull. Numerical char- these as relatives ("Verwandten") of acteristics must be viewed with caution. Cricotopus. To what extent some of these Figures cited in this paper were arrived at names should be retained as genera or even by constant revision as new specimens be- as subgenera is an open question. came available. Although a single most METHODS AND MATERIALS representative figure may be given, devi- Specimens used for the current study were col- ation from that figure is the rule. Com- lected principally in Ohio over a period of more than monly a deviation of 10 to 15% or even 50 years. Nearly all parts of the state are represented more may be expected in the case of leg ra- but particular attention has been accorded the island tio; antennal ratio varies even more. The area of western Lake Erie, which is particularly rich in . Naturally many specimens have been latter is probably best determined on slide- taken in the vicinity of Columbus and Oxford. For- mounted material that has never been al- tunately I have had the opportunity of collecting lowed to dry. Bristle counts on various rather extensively also in New York (Ithaca area) and parts of the body tend to be highly variable Michigan (Douglas Lake area). The majority of specimens, about 1350, are on points; about 500 are and are useful only where marked differ- in the form of permanent mounts in diaphane on ences occur. slides. Many of the latter have been reared so that lar- val and pupal exuviae are available, mounted on the Several species have been deliberately same slide with the adult. All specimens have been excluded from the discussion and keys. The examined critically. occurrence of C. tremulus in the Nearctic region is questionable. Early Nearctic KEYS TO ADULTS records should probably be referred to Systematists quite naturally have given C. slossonae. It is possible C. slossonae is a more attention to males than to females. In Nearctic form of C. tremulus. A second numerous instances the latter have been de- species, C. oceanicus, was inadequately de- scribed rather casually and briefly in terms scribed by Packard in 1869, probably from of the male. Evidence currently available teneral material, and has not been recog- suggests that it is hazardous to assume any nized since that time. A third species, particular degree of difference between the C. geminatus, described by Say in 1823, sexes. Unfortunately in a number of in- lacks the support of any solid records. stances only one sex is known. Males and Early workers limited the genus females are therefore keyed separately. If a Cricotopus to species with bicolored legs, sex is unknown it is omitted from the keys. hairy eyes and small or no pulvilli. Follow- In the couplets, characteristics enclosed in ing Edwards (1929), later workers placed brackets should be useful but are not neces- greater emphasis on the scutal hairs. Spe- sarily contrasting. The keys have been con- cies with minute, decumbent hairs were structed to accommodate both dry and included in Cricotopus even though they slide-mounted specimens by the use of lacked the whitish markings usually associ- multiple characteristics. For a variety of 76 M. W. BOESEL Vol. 83 reasons certain names are excluded from 4. Genitalia yellow-white; [abd 1 and part of abd the keys. Such exclusions have been dis- 2 greenish; rest of abd largely blackish, darker cussed in the introduction. posteriorly] C. fugax 4. Genitalia dark (5) Abbreviations adopted for use in the 5. Scutellar hairs sparse, largely confined to a keys and descriptions follow. All have ap- single transverse row; scutal ground color typi- peared previously in the literature. In cally pale (yellow, green, light brown); humeri Cricotopus, wing veins clearly expressed and pale; tarsal claws acute (fig. 1), not apically enlarged (6) reaching the wing margin are presumed to 5. Scutellar hairs numerous, scattered; scutal be Rl5 R2+3, R4+5, M, Cui and Cu2. ground color dark brown or black, including hu- Subcosta and the anal veins are relatively meri; tarsal claws, at least of mid legs, apically en- weak. Costa forms the anterior wing mar- larged, pectinate (fig. 2) (7) gin and may or may not extend beyond the 6. Scutum typically with dark greenish ground color and black vittae; LR 0.59; AR 1.3; abd tip of R4+5. blackish; scutellum usually blackish; C only L: total length, excluding antennae. slightly produced C. infuscatus WL: length of wing, from arculus to 6. Scutum typically with yellow ground color and tip. WW: maximum width of wing. AR: contrasting black vittae; LR 0.70; AR 1.7; abd yellowish or olive brown; scutellum usually more antennal ratio; terminal flagellomere/ or less yellowish; C distinctly produced C. polttus remaining flagellomeres. th: thorax, tho- 7'. Halteres blackish; scutum more or less pru- racic, abd: abdomen, abdominal, abdom- inose; basistyle with a single large basal lobe; inal segment, w, ww: wing, wings. fCu: scutellar bristles in a single transverse row; arculus cubital fork, f, ff; If, 2f, 3f: femur, femora; black C. nostocicola 7. Halteres yellowish; scutum shining; basistyle fore femur, mid femur, hind femur, t, tt; It, with 2 small basal lobes (fig. 3); scutellar bristles 2t, 3t: tibia, tibiae; fore tibia, mid tibia, scattered, not in a row; arculus yellow or brownish hind tibia, x, xx; lx, 2x, 3x: tarsus, tarsi; yellow C. baptistensis fore tarsus, mid tarsus, hind tarsus. x x , 8. abd 1 olive green; [anterior tergites behind abd 1? 2 1 greenish or greenish with a brown saddle or x3, X4, x5: 1st, 2nd, 3rd, 4th, 5th tarsal band; posterior tergite's velvety brown, incisures segment. LR: leg ratio; lxx/lt. variable; scutum shining dark brown; It largely whitish; lx brown; pronotum in lateral view nar- KEY TO MALES row above, gradually widened to base, not flar- ing] C. olivetus 1. Legs uniformly clear yellow, including ff; 8. abd 1 yellow-white; at least one tergite behind [ww milky, veins glassy clear; LR 0.55; abd seg- abd 1 entirely or partially yellow-white (9) ments largely dark above, light below, sometimes 9. abd 1 and 2 uniformly yellow-white or nearly darker posteriorly and appearing black-banded; so; [scutellar bristles fine, largely confined to a R2 + 3 slightly curved, ending halfway between single transverse row; scutum, scutellum and K\ and R4 + 5; pronotum posteriorly depressed postnotum black; incisures 3-4 and 4-5 yellow- and set off from scutum] C. flavipes ish or smooth; white band almost confined to 1. Legs variously darkened, infuscate yellow or basal half of It] (10) distinctly bicolored (2) 9. abd 2 not similar to abd 1 in coloration, with 2. tt not partly white but sometimes infuscate or more than a dorsomedial black spot or suggestion darker at ends; abd except for genitalia never with of a brownish saddle or abd 4 and 5 more than half distinct yellow-white markings (3) yellow-white (11) 2. At least It distinctly ringed yellow-white; abd 10. lx uniformly dark brown; dististyle fusi- usually partly yellow-white or shining light form, distinctly expanded at middle; terminal olive-green (8) peg of dististyle long, yellowish and apically 3. R2 + 3 weak, nearly straight; distance between sharp C. varipes tips of Rt and R2 + 3 about 2 times distance be- 10. lx with x2 or more pale; dististyle sub- tween R2+3 and R4+5; {LR 0.51; ww brown- cylindrical, only slightly broader at middle; ter- ish, veins slightly darkened (yellowish in slide minal peg of dististyle short, brownish and mounts); abd segments largely dark above, light apically dull C. slossonae below, sometimes yellowish posteriorly and ap- 11. abd 4 and 5 similarly marked, with anterior half pearing yellow-banded; pronotum nearly in line or more yellow-white, the division between col- with scutum; genitalia dark] C. elegans ors being vertical; [It largely yellow-white, nar- 3. R2 + 3 relatively strong, curving toward C; dis- rowly black basally, broader apically but distinctly tance between tips of Ri and R2 + 3 equal to or more than half pale; scutum yellow with 3 black less than' distance between tips of R2 + 3 and vittae; scutellar bristles fine, hairlike, leaning R4 + 5;LR 0.58-0.75 ."...(4) medially] C. triannulatus OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 77

11. abd 4 and 5 dissimilar or scutellar bristles KEY TO FEMALES spinelike or It with basal black band longer than 1. Cerci elongate, expanded at base and apex apical black band (12) and tipped with 6-8 strong bristles; [legs rather 12. Scutellar bristles spinelike, straight and stiff uniformly yellowish brown; 3t spur long, and/or It with basal black band longer than apical straight] C. absurdus black band (13) 1. Cerci short, not apically expanded and with nu- 12. Scutellar bristles fine, inconspicuous, curved merous short bristles (2) and leaning medially and It with apical black band 2. Legs uniformly clear yellow; [ww distinctly normally distinctly stronger than basal black milky, veins glassy clear; LR 0.55; R2 + 3 strong, band (16) ending halfway between Ri and R4 + 5; 13- lx with long hairs; [prescutellar area yellow; pronotum posteriorly depressed above and set incisures 2—3 and 3—4 commonly more off from scutum] C. flavipes broadly yellow-white than more posterior 2. Legs entirely or partially darkened (3) incisures] C. flavibasis 3. It not distinctly ringed with white (4) 13- lx with short hairs (14) 3. It distinctly ringed with white (9) 14. Prescutellar area black; scutum nearly all black; 4. 2xi and 3xj distinctly white-banded; abd 1, 5 2f and 3f light basally, grading into dark and 6 yellow-white C. junus apically C. tricinctus 4. 2xi and 3x[ not white-banded; abd 5 and 6 14. Prescutellar area yellow; scutum yellow with dark (5) blackish vittae; 2f and 3f largely yellow-white 5. R2+3 weak or evanescent, almost straight, rather sharply separated from black apex (15) reaching C near R4 + 5; [ww with brownish 15. abd 1 mainly and narrow margins of other ter- veins, not iridescent, membrane only vaguely gites yellow-white; incisures 3—4 and 4—5 usually whitish; in dark specimens, abd dark above; in- yellowish C. sylvestris paler specimens, abd 1 and 7 and sometimes in- 15. abd 1, 4 and 7 typically yellow-white; abd 4 cisures yellow-white; sternites 1 to 6 or 7 whit- sometimes with a black spot and abd 7 partly or ish] C. elegans almost wholly black; abd 2 and 5 variably yellow- 5. R2+3 strong, distinctly curved and reaching C white anteriorly; incisures variable C. trifasciatus about halfway between tips of K\ and R4 + 5 (6) 16. abd 4 with anterior third or fourth brown- 6. abd 1 greenish, rest of abd yellow-brown to black, the rest yellow-white; [scutum infuscate black, greenish below; legs sordidly yellow, some- yellow to brownish with yellow humeri; LR 0.62; times darker at joints C. fugax abd 1, a fourth of abd 2, incisures 2—3 and 3—4, 6. abd 1 black, brown or yellowish brown, similar posterior two-thirds or more of abd 4 and anterior to immediately succeeding segments; legs largely fourth or more of abd 5 yellow-white; incisures brown or black, tt sometimes slightly paler or 5—6 and 6—7 variable] C. diversus coxae and bases of ff yellowish (7) 16. abd 1 and 4 entirely yellow-white (17) 7. LR 0.66; C strongly produced beyond tip of 17. 1A extending far beyond fCu; yellow-white R4+5; abd yellowish brown; long posteroventral bands of abd 1 and 4 extending over anterior third margin of cerci slightly emarginate C. politus or fourth of abd 2 and 5; incisures 2—3, 5—6, 6—7 7. LR 0.55-0.58; C only slightly produced be- and 7—8 variably yellowish; pronotum in lateral yond tip of R4+5; abd dark brown or black; long view wide dorsally and ventrally, intermediate posteroventral margin of cerci very slightly area constricted, dorsal lobes flaring (fig. 4); arched (8) scutellum with fine, inconspicuous hairs; LR 8. Scutellar hairs few, largely confined to a single about 0.67; AR about 1.8; ww with red-purple- transverse row; humeri pale; halteres yellowish; blue reflections; Ix2/lx! 0.50 C. trifascia scutal ground color typically more or less green- 17. 1A ending about opposite fCu; abd 7 and 8 ish; coxae, trochanters and bases of ff yellow; cerci black; pronotum in lateral view not constricted apically acute C. infuscatus medially, the dorsal lobes not appreciably flaring; 8. Scutellar hairs numerous, scattered, not scutellum with fine hairs largely in a transverse confined to a single row; humeri dark; halteres row; LR about 0.5—0.6; AR about 1.1—1.7; ww blackish; scutal ground color typically brown- with largely bronze reflections; \x2/\x\ 0.58 or ish; legs entirely dark; cerci apically broadly more (18) rounded C. nostocicola 18. It broadly darkened apically, narrowly darkened 9. Preapical antennal bristle absent; It with basal basally; scutum largely blackish; abd 5 black; black band longer than apical black band and/or Ix2/lxi 0.61; basistyle tapering to narrow apex; scutellar bristles stiff, straight, spinelike, forming pronotum in lateral view rather uniform in width a transverse row (10) from dorsum to venter (fig. 5) C. bicinctus 9. Preapical antennal bristle present; It with apical 18. It narrowly darkened apically, nearly all white; black band longer than basal black band; scutellar scutum dull yellow with dark brown vittae; abd 5 bristles fine, hairlike, leaning inward in a single narrowly yellow-white anteriorly; Ix2/lxi 0.67; row (13) basistyle only slightly wider basally than apically; 10. At least one tergite in addition to abd 1 all or pronotum in lateral view narrow above, gradually nearly all yellow-white; abd 1, 4 and 7 typically widening to base (fig. 6) C. vierriensis yellow-white (11) 78 M. W. BOESEL Vol. 83

10. Tergites behind abd 1 in no case all yellow- entirely black; LR 0.53; scutellum and postnotum white or yellow-white with a dark saddle —(12) usually concolorous; veins in area of rm brownish, 11. Scutum yellow with sharply defined black vit- darker than posterior veins; pronotum in lateral tae; prescutellar area yellow; 2f and 3f largely view almost uniformly wide from dorsum to ven- yellow-white with sharply defined apical black ter (fig. 5) C. bicinctus band C. trifasciatus 19- It narrowly black apically, hardly darkened 11. Scutum with dark ground color; prescutellar basally, about VA or more whitish; scutum yellow- area more or less darkened; 2f and 3f light bas- ish brown with darker vittae; LR 0.48; scutellum ally and dark apically without sharp line of usually yellowish; postnotum brownish; veins in separation C. tnanctus area of rm not darker than posterior veins; 12. Incisures of abd 4 and 5 usually more widely pronotum in lateral view dorsally narrow, gradu- yellow-white than those of other segments; L 2.0 ally widening to base (fig. 6) C. vierriensis mm C. sylvestris 12. Bases of abd 3 and 4 more broadly yellow- DISCUSSION white than those of other segments; L 4.0 mm C. flavibasis The area covered in this study is com- 13. abd 5 largely or entirely yellow-white (14) prised of the 22 states located north and 13- abd 5 largely or entirely brown or black (15) east of the southwestern corner of Missouri. 14. abd 4 and 5 largely yellow-white; scutum yel- low with 3 brown vittae; It white with narrow One species has been found only in apical and very narrow basal black band, the bands Ontario, Canada, at a latitude that sug- not sharply defined; seminal receptacles ovate, gests it should occur in the United States. about 1.8 times as long as wide, evenly rounded at Of the 21 species listed, 17 have been taken both ends C. triannulatus in Ohio. Order of treatment is on the basis 14. abd 5 and 6 yellow-white; scutum usually brown with yellow humeri; It white with narrow of priority. basal black band and broader apical band about V3 length of It, the black bands rather sharply de- (FABRICIUS) 1794 fined; seminal receptacles about 1.9 times as long Although originally described from as wide, evenly rounded posteriorly, slightly to Europe, the species is widely distributed in distinctly narrower anteriorly C. diversus the United States from coast to coast, hav- 15. abd 1 and 2 entirely yellow-white or largely olive green; more posterior tergites darker in ing been reported from New Jersey coloration (16) (Johnson 1900), Illinois (Johannsen 1905), 15. abd 2 brown-black; abd 4 yellow-white (18) Kansas (Tucker 1907), Connecticut 16. abd 1 and 2 olive green, usually not sharply (Britton 1920), New York (Johannsen contrasting with rest of abd; abd 2 sometimes with brownish saddle; It about 3/s white, the 1928) and California (Darby 1962). It is not apical black band less than XA length of It, with generally abundant. In his early work, merging coloration C. olivetus Johannsen (1905) had no records for New 16. abd 1 and 2 yellow-white, usually rather York; Malloch (1915) had only a single sharply contrasting with rest of abd; It only about specimen from Illinois; Roback (1957) half or slightly more white, the apical black band almost reaching middle of It, with colors rather apparently had no specimens from the sharply defined (17) Pennsylvania area; I have only 2 specimens 17. lx entirely dark brown C, vanpes from Ohio, both taken in July in the island 17. lx with at least lx2 whitish C. slossonae area of western Lake Erie. However, Darby 18. 1A extending beyond fCu as a strong vein; (1962) found the species to be abundant in pronotal lobes conspicuous, flaring; pronotum in lateral view wide above and below with constric- California rice fields and Menzie (1980) tion in intermediate area (fig. 4); abd incisures of- found C. sylvestris to be the dominant spe- ten yellowish; Ix2/lxi 0.48; w membrane with cies living in Myriophyllum spicatum in the red-purple-blue-green iridescence; [scutum yel- Hudson River Estuary. low with brown vittae; LR 0.68; It narrowly black basally, broadly black apically] C. trifascia Species of the C. sylvestris group, some- 18. 1A weak beyond fCu; pronotal lobes nearly times generically placed in Isodadius or meeting medially, not conspicuous; pronotum in Eucricotopus, have been extremely difficult lateral view not medially constricted; abd in- to separate. Edwards (1929) noted a high cisures usually dark; IX2/IX1 0.60; w membrane reflections predominantly bronze (19) degree of variability. Hirvenoja (1973) 19- It broadly black apically, narrowly black basally, pictured 3 color variants of the male of not much more than half whitish; scutum almost C. sylvestris: strongly pigmented, normal OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 79 and weakly pigmented. When tergite 4 tively. The difficulty is to some extent of the abdomen is light, resemblance to philosophical and revolves about our con- C. trifasciatus is strong. Malloch (1915) cept of species. It has long been known that separated his C. flavibasis from C. sylvestris species exhibit different traits in different on the basis of the bearded fore tarsus parts of their range. Geographically sepa- but Edwards (1929) mentioned a slight rated populations are not likely to be pre- fore tarsal beard on most specimens of cisely the same because selective factors and C. sylvestris which he examined. Hirvenoja mutations are quite certain to be different. (1973) listed 20 possible varieties and syno- We should expect populations to adapt to nyms for this species. LeSage and Harrison micro-habitats and to exhibit correspond- (1980) noted that color pattern of Ontario ing featural differences. Widespread spe- specimens is extremely variable. The lar- cies are almost inevitably highly polytypic vae and pupae of C. sylvestris have never and tend to accumulate correspondingly been satisfactorily separated from those of many names. Related taxonomic problems C. trifasciatus and C. tricinctus. Hirvenoja can often be resolved only when long series (1973) presented keys which presume to of specimens are available and when com- identify these stages, but they seem to be plete life histories are known. In the pres- unreliable when applied to my reared ma- ent instance evidence currently seems to terial. Differences in the pupae involve favor the use of C. trifasciatus for our spe- size, form and details of shagreen and re- cies. All stages are closely similar to those spiratory organs. According to Hirvenoja of European material. As in Europe, we (1973) specimens collected in early spring have a larger form and a smaller, more differ from those collected in summer. common form. Furthermore there is essen- The species has often been reported as tially the same relationship to C. tricinctus doing severe damage to water-lily leaves. and C. sylvestris with respect to adult fea- Of the in California rice tures, and the immatures apparently are fields, C. sylvestris is second in abundance identical. to C. bicinctus, larvae occurring in Spirogyra Apparently C. trifasciatus is a wide- and other plants and living in tubes on the spread and highly variable Holarctic spe- plants but also on the mud surface, their cies. Adults occur throughout the summer food including diatoms, green algae and months. In Illinois they are present from occasionally also germinating seeds and April to October (Malloch 1915). Judd leaves of rice plants (Darby 1962). Clement (1953) recorded 2 peaks of emergence in et al (1977) considered C. sylvestris to be the Ontario, Canada, in July and October. most important chironomid doing damage Eggs are deposited in parallel gelatinous to rice plants in some areas of California. ribbons on floating vegetation and debris Hirvenoja (1973) associated larvae with near pond or stream margins (Johannsen waters having an abundance of vegetation 1937); sometimes large floating gelatinous and plant residues, where they may with- masses occur (Malloch 1915). The larvae are stand low oxygen levels, desiccation and yellow or greenish yellow to reddish sewage contamination. In winter larvae oc- (Malloch 1915, Johannsen 1937). They cur on plants but more abundantly in sedi- feed on a variety of vegetation including ments (Menzie 1980). leaves of Potamogeton, Polygonum, Nuphar and Nymphaea (Hirvenoja 1973, Johannsen CRICOTOPUS TRIFASCIATUS (MEIGEN IN PANZER) 1813 ( = CRIC0T0PUS REMUS SUBLETTE 1964, N. SYN.) 1937), mining in the leaves which they There is understandably some disagree- tend to skeletonize (Berg 1950). In a small ment with respect to the occurrence of limestone stream with heavy-metal pollu- C. trifasciatus and C. tricinctus in America. tion in Ohio, larvae occurred in small num- If Palearctic and Nearctic representatives bers but were absent in the most heavily are specifically distinct, our designations polluted part of the stream which sup- should be C. remus and C. lebetis respec- ported large numbers of C. bicinctus and 80 M. W. BOESEL Vol. 83

C. infuscatus (Winner et al 1980). Malloch lotus leaves, the following were also pres- (1915) found larvae in a clear-water reser- ent, listed in order of abundance: Endo- voir for city water supply. Larvae typically chironomus nigncans, Polypedilum convictum live in silken tubes within the feeding and Parachironomus tenuicaudatus. In Ohio channels which they make into the meso- adults have been taken in every month phyll (Wirth 1957). Larvae normally from May to August. The following coun- overwinter (Danks 1971). Pupation occurs ties are represented: Franklin, Butler, in the channels, the pupal stage lasting Ottawa, Ashtabula, Columbiana, Tusca- about 1.5—3 days; pupae swim free rawas, Erie, Lake, Mahoning, Carroll, into open water where adults emerge Jefferson, Auglaize, Harrison, Guernsey (Berg 1950). and Meigs. I also have specimens from Hirvenoja (1973) recognized 2 forms of Ithaca, NY. C. trifasciatus, a larger ("grossere") and a (MEIGEN) 1818 smaller ("kleinere") form. Actually there Currently this species is widespread and seems to be almost infinite variation in the abundant in both Europe and America. It species. This variation applies to size, is probably the most abundant species of color, chaetotaxy and dimension of parts. Cricotopus in the Ohio region. Evidently In the case of a series of reared specimens this was not always so. Johannsen (1905) from Squaw Harbor at Put-in-Bay, Ohio, had only several specimens; Malloch (1915) all individuals except one have a single row apparently also had very limited material. of strong bristles on the scutellum, as is Simpson and Bode (1980) suggested that usual. One specimen, however, has the scu- C. bicinctus is relatively most abundant tellar bristles scattered and irregularly where stresses eliminate other species. In placed. This is obviously a variant al- Michigan larvae were shown to be particu- though the trait is normally considered to larly resistant to electroplating wastes with be of specific significance. The fourth ab- chromium, cyanide and copper and also to dominal segment may be pure yellow- low oxygen levels (Surber 1959). In the white or all dark, with all variations be- study of a small stream receiving effluent tween from a small spot to a large saddle. containing copper, chromium and zinc A light form has the anterior 4th or 3rd of from a metal-plating industry, C. bicinctus the 2nd segment yellow-white and inci- was the dominant chironomid in the area of sure 5—6 broadly yellow-white; the 7th pollution whereas in the recovery area and segment is variously marked with black elsewhere in the stream the dominant spe- and white. A dark form has abdominal seg- cies was C. infuscatus (Winner et al 1980). ment 3 all black and incisures 2—3 and 5—6 Rosenberg and Wiens (1976) found that entirely black. the species responded positively to crude In 1943, many larvae of C. trifasciatus oil and petroleum products contamination. were collected in Squaw Harbor (Put-in- Rosenberg et al (1977b), on the basis of Bay, Ohio, July 16) from the upper and laboratory experiments, even suggested a lower sides of the older leaves of water lotus beneficial effect of crude oil on C. bicinctus (Nelumbo lutea). About 75% of larvae ex- for larvae were always more abundant on amined were heavily parasitized by round- oiled artificial surfaces than on unoiled sur- worms. The worms were active and faces. Larvae occur in ponds (Judd I960, occupied most of the space in the larvae, 1964), rivers (Surber 1959) and creeks often excluded only from the head and (Winner et al 1980). The species is the part of the thorax. Emergence of the para- most abundant member of the Ortho- sites did not result in the immediate death cladiinae in California rice fields (Darby of the host. Some larvae were alive 3 days 1962), preferring locations where water is after emergence. Although C. trifasciatus moving most rapidly. In creeks larvae tend was the most abundant species on the water to be most abundant where the stream OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 81

forms cascades (Paine and Gaufin 1956). Nearctic material specifically distinct The species often occurs in the same gen- under the name of C. lebetis. The eral environment with C. trifasciatus and nomenclatorial problem relative to wide- C. sylvestris if both algae and higher spread species has been discussed above. plants are present (Buckley and Sublette For the present I am inclined to consider 1964, Winner et al 1980, Darby 1962, C. lebetis the Nearctic form of C. tricinctus. Judd 1964). Although C. tricinctus is here treated as spe- There are probably at least 3 generations cifically distinct from C. trifasciatus, it is per year. In Northwest Territories over- conceivable that the former is in reality wintering occurs mainly in the second lar- only a dark form of the latter. It is interest- val instar (Rosenberg et al 1977a). Males ing to note that Hirvenoja's larger form of commonly swarm several feet above the C. trifasciatus has leg coloration which is ground. Oviposition, which occurs late in usually associated with C. tricinctus. Early the evening or early in the morning, is ac- April specimens of C. tricinctus may be al- complished as the female skims the water most altogether black, including the entire surface and dips her abdomen into the scutum, together with all of the 7th and water in flight (Darby 1962). Apparently much of the 4th abdominal segments. larvae are associated with a wide variety of In Europe larvae of C. tricinctus inhabit aquatic plants but Darby (1962) noted ponds, lakes and slow-flowing waters them particularly abundant in masses of where they feed on leaves of Potamogeton and Spirogyra; this alga, together with desmids probably other plants (Hirvenoja 1973). In and diatoms, also serves as food. Early lar- the littoral zone of Lake Texoma, Sublette vae migrate readily but late larvae tend to (1957) found larvae most frequently on remain in their tubes (Darby 1962), which Potamogeton. Paine and Gaufin (1956) re- are thin and transparent. Adults show a ported the species from Lytle Creek in wide degree of variation with respect to Ohio. Mason and Sublette (1971) collected pigmentation; October and November C. lebetis from the Ohio River near specimens tend to be deep black; those of Cincinnati. I have specimens from counties midsummer are often light brown. In some Butler, Ottawa and Clermont in Ohio. individuals the white abdominal bands are CRICOTOPUS TRIANNULATUS (MACQUART) 1826 obscured. Structural and dimensional vari- This was long considered to be essen- ations are also common. Females may have tially a northern European species. Re- only 4 joints in the antennal flagellum. In cently, however, LeSage and Harrison Ohio, adults occur from April to Novem- (1980) reported it from Canada, at the same ber. I have records from the following time declaring C. exilis a synonym. Origi- counties: Butler, Clinton, Ottawa, Erie, nally C. exilis was described by Johannsen Lucas, Jefferson, Muskingum, Morgan, (1905) from New York where larvae inhabit Franklin, Auglaize, Fairfield, Licking, the rocky bottom of a shallow swift creek Shelby, Ashtabula, Tuscarawas, Harrison, (Johannsen 1937) in the vicinity of Ithaca. Belmont, Guernsey, Lawrence and Scioto. The distribution is now known to extend I also have specimens from Michigan, New from Delaware and New Jersey westward York and Delaware. to Wisconsin (Bray and Triplehorn 1953, Johannsen 1952, Sublette and Sublette CRICOTOPUS TRICINCTUS (MEIGEN) 1818 ( = CRIC0T0PUS LEBET1S SUBLETTE 1964, N. SYN.) 1965). Malloch (1915) did not find it in Both Schiner (1864) and Johannsen Illinois. In Ohio C. triannulatus is ex- (1905) considered this to be a variety of tremely abundant at times in the island C. trifasciatus. Later Edwards (1929) and area of western Lake Erie in the shallow Johannsen (1952) accorded C. trkinctus spe- water adjacent to land where the bottom is cific rank. Recent American workers, fol- composed of rocks and boulders and where lowing Sublette (1964), tend to consider wave action may be severe (Shelford and 82 M. W. BOESEL Vol. 83

Boesel 1942). In Ohio k occurs also in lim- trarily. LeSage and Harrison (1980) found a ited numbers in the shallow water of small puzzling adult form intermediate between hard-bottom creeks (Paine and Gaufin C. varipes and C. slossonae which they 1956, Winner et al 1980). The yellowish thought might actually represent a third green larvae construct silken tubes. Adults species. Color variations are common. occur in Ohio from April to November. I Normally the first and second abdominal have records from the following counties: segments are all white, but I have speci- Butler, Ottawa, Erie, Lucas, Franklin, mens with a strong brown saddle on the Ashland, Lake, Mahoning, Harrison, second segment. The light margins of ab- Muskingum, Brown, Jefferson and dominal segments 3 and 4 are variably Belmont. I also have specimens from present and segments behind 4 may have Ithaca, NY. light margins. Essentially all gradations of CRICOTOPUS POLITUS (COQUILLETT) 1902 fore tarsal pigmentation occur from partly This species has been reported from the white to all black. Under the circum- east coast to Kansas and Colorado and from stances I have unified collection data for Ontario, Canada, to Florida (Tucker 1907, C. varipes and C. slossonae. LeSage and Harrison 1980, Sublette and Rosenberg and Wiens (1976) indicated Sublette 1965). Not much is known about that C. varipes shows a strong positive re- its ecology although it has been taken from sponse to crude oil contamination but not lakes (Mason and Sublette 1971), reservoirs to the degree shown by C. bicinctus. (Iovino and Miner 1970) and streams Winner et al (1980) found that, in a small (Paine and Gaufin 1956). Mason and stream subject to heavy-metal pollution, Sublette (1971) collected it from the Ohio C. varipes and C. slossonae were absent in the River near Cincinnati. Paine and Gaufin immediate area of pollution but were pres- (1956) found it to be restricted to clean ent in all stations of the recovery area; both water in Lytle Creek, Ohio. The species has C. bicinctus and C. infuscatus were abundant been abundant in the island area of western in the pollution area. Lake Erie where larvae are found on rocks of The species or combination of species is the Hydropsyche-Goniobasis community widely distributed from Northwest Terri- (Shelford and Boesel 1942). I have not tories to Florida and from Oregon and found it to be abundant elsewhere. Speci- Washington to the east coast (Sublette and mens have been collected on Pelee Island, Sublette 1965, LeSage and Harrison 1980). Canada. In Ohio adults occur in every Specimens have been taken in the follow- month from April to August. The follow- ing Ohio counties: Butler, Ottawa, ing counties are represented: Ottawa, Harrison, Belmont, Muskingum, Jackson, Erie, Franklin, Highland, Ashland, Butler Franklin, Brown, Ashland, Tuscarawas, and Ashtabula. Licking and Fairfield. Adults occur from CRICOTOPUS VARIPES (COQUILLETT) 1902 April to November. I also have specimens Unfortunately records for C. varipes are from New York, Michigan and Canada more or less untrustworthy due to the diffi- (Pelee Island). culty of distinguishing between this spe- CRICOTOPUS ABSURDUS (JOHANNSEN) 1905 cies and C. slossonae. Their larvae seem to Johannsen described the species from a be identical; pupae are separated with diffi- single female taken at Ithaca, NY. The only culty. Johannsen described the larva and other record is that of Paine and Gaufin pupa of C. varipes in 1905. Apparently he (1956) who collected 11 specimens from later considered the descriptions invalid for Lytle Creek (Clinton County, Ohio) where he omitted reference to them in his exten- Ordovician limestone forms the bottom. sive work in 1937. As indicated in the Associated species were Polypedilum discussion of C. slossonae, adult specimens illinoense and Cricotopus politus. The larvae occur which must be placed rather arbi- were found only in the clean water sections OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 83 of the stream. I have only 13 specimens male fore tarsus. However C. sylvestris may from Ohio, all from Oxford except for a have a slight beard (Edwards 1929). I have single specimen from Columbus. All are not seen specimens with a beard suffi- females. The male is unknown. Ohio col- ciently long to be separated from C. syl- lection dates range from May 24 to July 16. vestris. The immatures have not been Four species are known which are similar to described. Ohio records are lacking. This C. absurdus with respect to the highly un- may prove to be a form of C. sylvestris or usual female cerci; all are Neotropical C. trifasciatus. (Canal Zone, Puerto Rico, Peru). In one CRICOTOPUS SLOSSONAE MALLOCH 1913 species, both sexes have a brown abdomen Early Nearctic records of C. tremulus (Sublette 1967); in the other 3, both sexes probably represent misdeterminations of have the abdomen banded with yellow; one C. slossonae. Traditionally C. slossonae is similar to C. bicinctus. Roback (1962) has been regarded as closely related to noted males of species related to C. absurdus C. vanpes, differing principally in the color are typical Cricotopus except possibly for the of the fore legs and abdomen and in the metatibial spur which is unusually long, genitalia. However, individuals occur about 2.4 or more times the width of the which tend to close the gap between the apex of the metatibia; generally the length species. Separation of the immatures has al- in Cricotopus is only about equal to the ways been a problem. LeSage and Harrison width of the metatibial apex. (1980), working on a single Canadian CRICOTOPUS FUGAX (JOHANNSEN) 1905 stream, observed that C. varipes precedes Although Johannsen described the C. slossonae in spring emergence but suc- larva, pupa and both sexes of C. fugax, the ceeds it in fall. This suggests that C. varipes species is poorly known. Johannsen (1937) may be a dark form and C. slossonae a light found the bluish green larvae in tubes of form of a single species. My specimens rep- debris on rock surfaces in a shallow, swift resent many localities and do not reveal this creek. He indicated the larval labial plate is relationship. Although strongly tempted similar to that of C. trifasciatus. According to synonymize C. slossonae with C. varipes, I to Sublette (1966) the male genitalia am tentatively keying them as separate on closely resemble those of C. politus except the basis that they may be incipient for coloration. I have only 4 specimens ten- species. But due to the questionable nature tatively assigned to C. fugax, from New of some determinations I have combined York and Michigan, but lack records for collecting data for the 2 species under Ohio. Apparently the species has not been C. varipes. I believe they will ultimately positively identified and reported since it prove to constitute one highly variable was discovered by Johannsen. species. CRICOTOPUS FLAVIBASIS MALLOCH 1915 CRICOTOPUS INFUSCATUS (MALLOCH) 1915 Both male and female were originally (=CRICOTOPUS ARATUS ROBACK 1957, N. SYN.; described from Illinois. Malloch (1915) ap- =CRICOTOPUS CERIS ROBACK 1957, N. SYN.) parently had 3 specimens (Sublette 1970). Malloch (1915) originally described The species has since been recorded from C. infuscatus from Illinois. Hudson (1971) South Dakota (Hudson 1971); British later reported it from South Dakota. In Columbia and Alberta, Canada, (Cannings Ohio it proved to be abundant in a small 1975). However it is not well known. limestone stream subject to heavy-metal Sublette (1970) noticed the wing venation pollution; it was second only to C. bicinctus is similar to that of C. trifasciatus and male in the area of heaviest pollution and domi- genitalia resemble those of C. remus, which nant in the recovery area (Winner et al I believe to be a form of C. trifasciatus. 1980). That study provided material for an Malloch (1915) separated C. flavibasis from extensive study of variation in the species. C. sylvestris because of the long hairs on the Size and intensity of color are extremely 84 M. W. BOESEL Vol. 83

variable. In paler specimens mid and hind larvae occurring in only half of the streams femora tend to be gradually darkened from studied and in only 10% of the samples. tip to base but in darker specimens they They believed the larvae to be saproxenous. may be completely blackish except for the In a small limestone stream near Oxford, base. The scutellum varies from infuscate Ohio, larvae were present in small num- yellow to nearly black. Some females are bers. In 1980 LeSage and Harrison synony- smaller than C. aratus which has been set mized C. ithacanensis with C. trifascia and off largely on the basis of size. Female an- recorded the species from Ontario. I have tennal segments vary in length; sometimes 49 adults from Ohio, with collection dates adjacent flagellomeres are fused. Appear- from May to August; counties represented ance of genitalia varies with viewing angle. are Butler, Ottawa, Ashland, Guernsey, Male genitalia of C. infuscatus as shown by Muskingum and Franklin. I also have Malloch (1915) and C. ceris as shown by adults from Michigan (Douglas Lake area) Roback (1957) represent slightly different and New York (Ithaca). views. In the former the inner edges of the basistyle are nearly coincident whereas in CRICOTOPUS VIERRIENSIS GOETGHEBUER 1935 the latter they are widely separated. The The species has only recently been re- triangular edge of the outer half of the ported from the Nearctic region by Oliver basistyle tends to disappear in the former (1977), who recorded it from Manitoba, view because it is turned inward. The basal Canada, and cited a single-specimen record appendages vary depending on degree of from Pennsylvania. Johannsen probably re- contraction or extension. Specimens which garded this as a variant or form of I originally identified as C. aratus and C. bicinctus for I have taken specimens in C. ceris are obviously only forms of the area of Ithaca, NY. The species was de- C. infuscatus. Larvae of a closely related scribed by Goetghebuer in 1935. In 1950 California species, Cricotopus fuscatus, occur Goetghebuer and Lenz listed C. vierriensis in colonies of the alga Nostoc (Wirth 1957). as a junior synonym of Cricotopus decorus, In Ohio C. infuscatus has been collected in described by Goetghebuer in 1927. the following counties: Butler, Lucas, Hirvenoja (1973) regarded C. decorus as a Guernsey, Franklin and Belmont. I also junior synonym of Cricotopus similis, de- have specimens from Michigan and New scribed by Goetghebuer in 1921; however, York. Adults occur in every month from he accorded specific rank to C. vierriensis. March to November. The early stages of C. vierriensis have been described as extremely similar to but sepa- CRICOTOPUS TRIFASCIA EDWARDS 1929 rable from C. bicinctus. Specimens which I Although known to occur widely in the have determined as C. vierriensis check very Palearctic region from England and France well with early descriptions of C. similis, southward and eastward to Palestine and suggesting the species may be identical. Sakhalin Island off the coast of Asia, this However, male genitalia as shown by species seems to be nowhere abundant. In Hirvenoja (1973) are very different. In America it has been known as Cricotopus Europe C. vierriensis larvae inhabit stand- ithacanensis, described by Sublette (1967) ing waters and can survive in waters with from a single misdetermined male in the high salt concentrations. Ohio records in- Cornell University collection. Roback clude the following counties: Butler, (1957) found the larva in Pennsylvania and Franklin, Ashtabula, Mahoning, Har- referred to it as Cricotopus sp. 1. Simpson rison, Belmont, Muskingum, Ottawa, and Bode (1980) recognized larvae col- Jefferson and Fairfield. Other states repre- lected from streams in New York as be- sented are New York and Michigan. Col- longing to the C. trifascia group. They lection dates for adults include every described larval distribution as "patchy," month from April to August. OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 85

CRICOTOPUS FLAVIPES JOHANNSEN 1942 larva and pupa. The male is unknown. Fe- The male, female, larva and pupa of this males should easily be recognized on the species were described by Johannsen from basis of the entirely brown fore leg, the specimens collected and reared by Berg in banding of the abdomen and the distinctly Michigan. Berg (1950) provided details of white-banded first tarsal segment of the the life history which are here briefly mid and hind leg (Roback 1957). Roback summarized. Adults occur from June to collected larvae from creeks with bottom of August. Late-instar larvae make linear rock, gravel and some mud. I have not seen mines in the submerged leaves of Potamo- the species. geton; mines tend to parallel the leaf mar- CRICOTOPUS NOSTOCICOLA WlRTH 1957 gins. Larvae remove all tissue between the Larvae of C. nostockola occur in colonies epidermal layers, leaving curved marks of the blue-green alga Nostoc (Wirth 1957) made by the mandibles. Apparently only and were originally described by Johannsen third- and fourth-instar larvae mine the (1937) under the name of Spaniotoma sp. G. leaves, early larvae living in the plant They attach the algal colonies to rocks and stems, where they overwinter. The larvae other objects in both lentic and lotic situ- probably feed on algae which they draw ations, feeding on the algal matrix; in into their mines. I have 5 specimens of C. California adult emergence peaks in March flavipes, 2 from Ohio (Middle Bass Island) and April, with light emergence in July and 3 from New York (Ithaca), adding and August (Brock I960). The species has 2 states to the single-state records of Berg. been recorded from California, Oregon, JOHANNSEN 1943 Montana, Connecticut, West Virginia and Larvae, pupae and adults of this species Tennessee (Johannsen 1937, Wirth 1957, were originally collected by Berg from the Brock I960, Beck 1980). In California, Huron River in Michigan. Berg (1950) Cricotopm fuscatus also occurs in the algae published details of the life history. Larvae and is separable from C. nostockola only in of the first, second and third instars mine the adult stage (Brock I960). I have only 9 in the coriaceous floating leaves of Potamo- specimens of C. nostockola from Ohio, all geton, riddling them with an irregular net- collected at Columbus in April. work of crisscrossing mines. Fourth-instar CRICOTOPUS DIVERSUS NEW SPECIES larvae were not found in the leaves in the Originally I anticipated that females of field but under laboratory conditions fed this species would prove to be C. junus be- on various parts of the plants. Adults cause of the abdominal coloration. How- occurred in Michigan from May to October ever leg coloration is conspicuously unlike (Berg 1950). Apparently the only other that of C. junus. In all of my specimens the published record for C. elegans is that of fore tibia is white, broadly black at the Roback (1957) who collected one specimen apex and narrowly black at the base. Fur- from a Pennsylvania creek having a variety thermore both mid and hind tibiae are of plants including Potamogeton. I have col- white, darkened at the ends; mid and hind lected 81 adults from April to August in tarsi are infuscate, gradually darkened Ohio, particularly from the island area of apically. In C. junus the fore leg is entirely western Lake Erie; islands represented are brown and the first tarsal segment of the South Bass, North Bass, Middle Bass, mid and hind leg are distinctly white- Green, East Sister, Ballast and Catawba. A banded (Roback 1957). In some respects single specimen was taken on Pelee Island C. diversus is superficially similar to the (Canada). Each of 2 counties, Butler and European C. festivellus as described by Erie, yielded 2 specimens. Hirvenoja (1973) and Goetghebuer and CRICOTOPUS JUNUS ROBACK 1957 Lenz (1950) and reported from Canada by This species was described from LeSage and Harrison (1980). However the Pennsylvania with respect to the female, male differs sharply in abdominal color- 86 M. W. BOESEL Vol. 83

ation. In C. diversus the yellow-white incisures 2—3 rather broadly and 3—4 band involving the fourth and fifth abdom- rather narrowly, posterior 3A to 7/s of abd 4 2 inal segments is broad, at least two-thirds and anterior /5 of abd 5; posterior incis- of the former being light. In C. festivellus ures vaguely lighter. Genitalia yellow- the band is narrow, less than half of the white; dististyle with several unequal ap- former being yellow-white. Also in C. ical bristles (fig. 7); inner lobe of basistyle diversus the second abdominal light band single, angular or apically rounded, de- is very narrow whereas in C. festivellus it pending on view (fig. 8). Color of abd 2 is broad. highly variable, ranging from largely black Males were swarming on Gibralter in dark specimens to largely yellowish, Island in Lake Erie on the evening of July particularly at the ends. 31, 1933. The species is known to range FEMALE. L 1.55 mm. WL 1.45 mm. from Michigan and Ohio eastward to New Terminal antennal flagellomere longer than York and Delaware. Early stages are un- preceding 3 combined. Preapical antennal known. On a number of occasions adults bristle present. Pronotum distinctly wider have been taken from windows inside ventrally in lateral view, yellowish to buildings on the Miami University brownish, bare. Scutum usually brown, campus. shining, with yellowish humeri. Scutellum MALE. L 2.5 mm. WL 1.6 mm. Head with a single slightly irregular row of yellow to light brown below antennae; fine hairlike bristles leaning medially. vertex brown. Antennal flagellum brown, LR 0.58. ff apically black, grading to yel- lighter basally; scape dark brown. AR lowish at base; It broadly (about half) 1.4. Palps brownish; palpal ratio white, apex broadly and base narrowly 6:6:15:18:33. Pronotum narrowing blackened; 2t and 3t white, slightly dark- gradually to dorsum in lateral view, not ened at ends; lx brown; 2x and 3x infus- flaring; yellow to brown, bare. Scutum cate, darker apically. w brownish with brown to blackish, shining; humeri yel- largely bronze reflections; 1A not strong lowish (light specimens yellow with brown beyond level of fCu. R with about 6 setae; vittae). Scutellum with fine inconspicuous R44-5 with about 3—5 setae, abd 1, 5 and bristles, leaning medially; dark brown, 6 yellow-white; abd 2, 3 and 4 sometimes like scutum (light specimens with scutel- posteriorly pale-margined together with lum pale brown, narrowly yellow anteri- narrow anterior margin of abd 2. Seminal orly). LR (Wit) 0.62. ff dark brown receptacles about 1.9 times as long as wide, apically, yellow basally, without sharp line evenly rounded and wider posteriorly, of division; 2t and 3t yellowish white, nar- narrow anteriorly. Cerci subtriangular to rowly darkened at ends, more broadly apically rounded. apically; It white, broadly darkened TYPES. Holotype: 1 8, slide mount labeled apically, narrowly basally, about half or a "Holotype" (specimen a), Put-in-Bay, OH, 21 June little more white; 2x and 3x light brown or 1946. Allotype: 1 9 , slide mount labeled "Allotype," same data as holotype. infuscate, lighter than lx, darker apically. Paratypes (slide mounts): 9 S 8, 2 9 9. Put-in- w brownish with largely bronze reflec- Bay, OH, 21 June 1946, 12 July 1944, 8 July 1942, tions, more or less iridescent along costal 26 July 1924, 9 July 1924, 30 June 1924; 18 . Mid- margin and rarely apically. R with about 5 dle Bass Island, OH, 10 Aug. 1945; 1 9 , Columbus, setae; other veins normally bare. Veins OH, 16 Apr. 1925. Paratypes (dry specimens on points): 3 8 8, 3 brownish; R2+3 quite distinct, reaching 9 9, Oxford, OH, 17 July 1976, 22 June 1973, 13 C about midway between Ki and R4+5; C June 1972, 26 May 1972, 28 Apr. 1938, 12 Oct. only slightly produced; 1A short, reaching 1937; 7 88, 8 9 9, North Bass Island, OH, 15 level of fCu. Halteres yellow. General ap- Aug. 1940, 26 June 1937, 19 July 1933, 15 July pearance of abd dark with 2 broad yellow- 1933, 10 July 1933; 2 July 1926, 9 July 1925; 33 8 8,49 9, Put-in-Bay, OH, 9 Aug. 1940, 27 July ish bands; abd brown with yellow-white as 1940, 18 July 1940, 24 June 1940, 20 June 1940, follows: abd 1 (rarely somewhat darkened), 30 June 1937, 24 June 1937, 23 June 1937, 21 June Ohio J. Sci. THE GENUS CRICOTOPUS IN OHIO 87

10

9 1 1 FIGURES 1-11. (1) Crkotopus infuscatus 6: tarsal claw of mid leg. (2-3) Cricotopus baptistensis 6: (2) tarsal claw of mid leg, (3) genitalia. (4) Crkotopus trifascia 6: pronotum. (5) Cricotopus bicinctus 6: prono- tum. (6) Crkotopus viernensis 6 : pronotum. (7-8) Crkotopus diversus 6 : (7) dististyle, (8) variations of inner lobe of basistyle. (9) Crkotopus baptistensis 6: apex of dististyle. (10-11) Cricotopus olivetus 6: (10) genita- lia, (11) apex of dististyle, another view.

1937, 1 Aug. 1933, 31 July 1933, 30July 1926, 29 Pelee Island, Canada, 23 July 1926, 25 July 1925; July 1926, 26 July 1926, 4 July 1926, ljuly 1926, 2 6 6, Ashland Co., OH, 22 May 1926; 2 66, 25 June 1926, 23 June 1926, 30 July 1925, 15 July Lancaster, OH, 8 May 1926; 7 66, 3 9 9, 1925, 10 July 1925, 8 July 1925, 4 July 1926, 1 Lockbourne, OH, May 1926, 23 May 1925; 1 6, July 1925, 30 June 1925, 26 June 1925; 1 6, Erie Columbus, OH, 29 May 1925; 2 9 9, Ithaca, NY, Co., OH, 2 July 1940, 7 6 6, 9 9 9, Middle Bass 18 June 1934, 27 May 1934; 2 9 9, Grove City, Island, OH, 2 July 1957, 27 June 1940, 6 July OH, 4 Apr. 1925. All types are currently in the 1937, 4 Aug. 1933, 7 July 1933, 28 June 1926, 24 Boesel collection. June 1926, 24 July 1925, 21 July 1925; 2 6 6, 2 CRICOTOPUS BAPTISTENSIS NEW SPECIES 9 9, Catawba Island, OH, 24 July 1933, 3 July This species is included here because it 1926, 11 July 1925; 1 6, Mackinac Island, MI, 15 July 1928; 1 6, Franklin Co., OH, 15 May 1928; occurs in Ontario, Canada, at a latitude lcT, 1 9, Trumbull Co., OH, 4 July 1927; 1 6, south of parts of Michigan and Maine and Muskingum Co., OH, 26 June 1927; 4 66, 1 9, is therefore likely to be found in the area of M. W. BOESEL Vol. 83

this study. The only available material to base, not flaring, with adjacent part of consists of 21 males taken between May 27 scutum slightly depressed. Scutum shining and May 31, 1970, by Dr. Carl P. Boesel. brownish black or black; humeri yellow- The species seems to be close to the ish; ground color slightly yellow in pale European Crkotopus tibialis which has bi- specimens. Scutellum dull black, with colored legs. long slender hairs in a transverse row. MALE. L 3.15 mm. WL 2.3 mm. AR Postnotum brownish black. LR (lx]/lt) 1.6. Pronotum brown, basally hairy. Scu- 0.63. ff brownish, extreme bases pale. All tum shining black. Dorsocentrals numer- tt largely whitish yellow with poorly de- ous, forming a broad confused row between fined pale brown or blackish band at base the median and lateral vittae, meeting be- and apex, broader at apex and very narrow hind the median vitta and occupying most at base, about VA of It whitish, xx pale of the prescutellar area, being sparse or ab- brown. Veins of w brownish; R4+5 bare; sent only medioposteriorly in that area. R with about 4 (1—7) bristles. Halteres Scutellum appearing brushy with scattered pale. Tergites of abd 1 and 2 olive green, hairs. LR (Ixx/lt) 0.67. Legs almost uni- shining, or abd 2 with brown saddle, more formly blackish brown. Claws of all legs posterior tergites with successively more apically enlarged, pectinate (fig. 2). R2 + 3 brown; posterior tergites all brown or strong, ending about midway between Rt brown except for incisures. Less heavily and R4+5. C not extended beyond end of pigmented specimens with abd 1—4 olive R4+5. Arculus yellow or brownish yel- green with only a suggestion of a brown low. Halteres whitish yellow. Entire abd saddle, especially on 3 and 4, 5 largely dark brown, intermediate segments with brown, 6—8 entirely brown, with incisures long hair almost evenly distrubuted over back to 5—6 smooth olive green. Genitalia tergites except posteriorly. Genitalia black. yellowish; basal appendage of basistyle Basistyle with double lobe (fig. 3). Disti- with subspherical anterior lobe bearing ex- style with an apical spine and a subapical tremely strong spines, posterior lobe in- peg at the base of a laterally directed trian- conspicuously hairy and variably triangular gular process (fig. 9). Anal point absent. in shape (fig. 10); dististyle with terminal TYPES. Holotype (slide mount labeled peg and bristle, subtruncate, with short "Holotype"): 1 8, Baptiste, One, 30 May 1970. but distinct surface hairs (fig. 11). Paratype (slide mount): 1 8, Baptiste, Ont., FEMALE. L 1.45 mm. WL 1.7 mm. An- 27 May 1970. tenna with preapical bristle. Pronotum Paratypes (dry specimens on points): 19 8 8, Baptiste, Ont., 31 May 1970, 30 May 1970, 27 May yellow to brownish, bare. Scutum shining 1970. All types collected by C. P. Boesel and cur- black, ground color slightly lighter. Scu- rently in the Boesel collection. tellum dull blackish, with row of fine bris- CRICOTOPUS OLIVETUS NEW SPECIES tles leaning inward. LR (lxi/lt) 0.61. It Abdominal coloration in this species is largely white except narrowly at base and suggestive of C. fugax but leg coloration more broadly at apex, lx entirely and uni- and S genitalia as figured by Sublette formly brown, w hyaline. R2 + 3 distinct, (1967) are conspicuously different. The lat- ending about halfway between Kx and ter are most similar to those of Cricotopus R4+5. C distinctly produced, abd 1 and 2 annulator as illustrated by LeSage and olive green; rest of abd dark brown. Semi- Harrison (1980); however I have no speci- nal receptacles subspherical, lightly mens agreeing with the abdominal color sclerotized, about 0.16 mm in diameter. pattern of C. annulator as shown by Genitalia whitish. Cerci anteroventrally Goetghebuer and Lenz (1950). acute. TYPES. Holotype: 1 cT, slide mount labeled MALE. L 2.7 mm. WL 1.8mm. AR 1.5. "Holotype," Put-in-Bay, OH, 30 June 1926. Pronotum yellow to brownish, bare; in lat- Allotype: 1 9 , slide mount labeled "Allotype," Put- eral view, narrow above, gradually widened in-Bay, OH, 14 July 1926. OhioJ. Sci. THE GENUS CRICOTOPUS IN OHIO 89

Paratypes (slide mounts): 7 6 6, 2 9 9, Put-in- Cannings, R. A. 1975 Some Chironomidae Bay, OH, 21 June 1946, 23 June 1926, 20 June (Diptera) new to British Columbia and Canada. J. 1926, 15 July 1925, 2 July 1925, 2 July 1924, 30 Entomol. Soc. British Columbia 72: 23—25. June 1924, 20 June 1924; 4 6 6, Middle Bass Is- Clement, S. L., A. A. Grigarick and M. O. Way land, OH, 17 July 1946, 28 June 1926, 24 June 1977 Conditions associated with rice plant in- 1926; 1 6, East Harbor, Catawba Island, OH, 11 jury by chironomid midges in California. Envi- July 1925; 1 9 , Franklin Co., OH, 15 May 1928; 1 ron. Entomol. 6: 91—96. 9 , Ashland Co., OH, 8 July 1927; 1 9 , North Bass Danks, H. V. 1971 Overwintering of some north Island, OH, 9 July 1925. temperate and arctic Chironomidae II. Chiro- Paratypes (dry specimens on points): 4 6 6, nomid biology. Canadian Entomol. 103: 2 9 9, Middle Bass Island, OH, 22 Aug. 1940, 28 1875-1910. June 1926, 24 June 1926; 8 6 6,4 9 9, Put-in- Darby, R. E. 1962 Midges associated with Bay, OH, 30June 1937, 23 June 1937, 1 July 1926, California rice fields, with special reference to 30 June 1926, 23 June 1926, 20 June 1926, 15 July their ecology (Diptera: Chironomidae). Hilgardia 1925, 5 July 1925, 2 July 1925; 1 9, Catawba Is- 32: 1-206. land, OH, 19 July 1937; 4 66,2 9 9, North Bass Edwards, F. W. 1929 British non-biting midges Island, OH, 26 June 1937, 2 July 1926, 9 July (Diptera, Chironomidae). Trans. Entomol. Soc. 1925; 2 66, Oxford, OH, 25 May 1937, 19 June London 77: 279-430. 1929; 4 6 6,2 9 9, Ithaca, NY, 2 July 1934, 7 Goetghebuer, M. and F. Lenz 1950 In; E. June 1934, 3 June 1934, 2 June 1934, 13 May 1934; Lindner (ed.), Die Fliegen der palaearktischen Re- 2 9 9, Franklin Co., OH, 15 May 1928, 13 May gion 13g (Lief. 162): 145-208. 1928; 1 9, Ashland Co., OH, 8 July 1927; 1 9, Hirvenoja, M. 1973 Revision der Gattung Tuscarawas Co., OH, 30 June 1927; 1 9, Cricotopus Van der Wulp und ihrer Verwandten- Greenville, OH, 29 May 1926; 1 9; Columbus, (Diptera, Chironomidae). Ann. Zool. Fennici OH, 29 May 1925. 10: 1-363. All types for C. olivetus were collected by Hudson, P. L. 1971 The Chironomidae (Dip- M. W. Boesel and are currently in the Boesel collec- tera) of South Dakota. Proc. South Dakota Acad. tion. In addition to the types I have specimens col- Sci. 50: 155-174. lected by Dr. C. H. Kennedy on Goose Island, MI, Iovino, A.J. and F. D. Miner 1970 Seasonal on July 10, 1928. abundance and emergence of Chironomidae of Beaver Reservoir, Arkansas (Insecta: Diptera). J. Kansas Entomol. Soc. 43: 197-216. LITERATURE CITED Johannsen, O. A. 1905 Aquatic nematocerous Beck, W. M., Jr. 1980 Interesting new chiro- Diptera II, Chironomidae. New York St. Mus. nomid records for the southern United States Bull. 86: 76-331. (Diptera: Chironomidae). J. Georgia Entomol. 1928 Order Diptera. In: M. D. Leon- Soc. 15: 69-73. ard (ed.), A list of the of New York. Berg, C. O. 1950 Biology of certain Chiro- Cornell Univ. Agri. Exp. Sta. Mem. 101: nomidae reared from Potamogeton. Ecol. Monogr. 687-868. 20: 82-101. 1937 Aquatic Diptera, Part III. Chi- Boesel, M. W. 1974 Observations on the Co- ronomidae: subfamilies Tanypodinae, Diam- elotanypodini of the northeastern states, with keys esinae, and Orthocladiinae. Cornell Univ. Agri. to the known stages (Diptera: Chironomidae: Exp. Sta. Mem. 205: 1-84. Tanypodinae). J. Kansas Entomol. Soc. 47: 1952 Family Tendipedidae ( = Chi- 417-432. ronomidae), except Tendipedini. Connecticut St. Bray, D. F. and C. A. Triplehorn 1953 Survey of Geol. Nat. Hist. Surv. Bull. 80: 3-26. the fauna of red and pin oaks in Delaware. Johnson, C. W. 1900 Order Diptera. Family Univ. Delaware Agri. Exp. Sta. Bull. (Tech.) Chironomidae. In: J. B. Smith (ed.), Insects of 297: 1-28. New Jersey, p. 1-755. Britton, W E. 1920 Check-list of the insects Judd, W. W. 1953 A study of the population of of Connecticut. State Geol. Nat. Hist. Surv. insects emerging as adults from the Dundas 1920: 1-397. Marsh, Hamilton, Ontario, during 1948. Amer. Brock, E. M. I960 Mutualism between the Midland Nat. 49: 801-824. Cricotopus and the alga Nostoc, Ecology I960 A study of the population of 41: 474-483. insects emerging as adults from South Walker Buckley, B. R. and J. E. Sublette 1964 Chi- Pond at London, Ontario. Amer. Midland Nat. ronomidae (Diptera) of Louisiana II. The limnol- 63: 194-210. ogy of the upper part of Cane River Lake, 1964 A study of the population of Natchitoches Parish, LA, with particular refer- insects emerging as adults from Saunders Pond at ence to the emergence of Chironomidae. Tulane London, Ontario. Amer. Midland Nat. 71: Stud. Zool. 11: 151-166. 402-414. 90 M. W. BOESEL Vol. 83

LeSage, L. and A. D. Harrison 1980 Schiner, J. R. 1864 Fauna Austriaca. Die oi Cricotopus species (Diptera: Chironomidae) from Fliegen (Diptera). Zweiter Teil. Verlag von Carl Salem Creek, Ontario. Proc. Entomol. Soc. Gerold's Sohn, Wien. 658 p. Ontario 111: 57-114. Shelford, V. E. and M. W. Boesel 1942 Bottom Malloch, J. R. 1915 The Chironomidae, or communities of the island area of western midges, of Illinois, with particular reference to Lake Erie in the summer of 1937. Ohio J. Sci. the species occurring in the Illinois River. Bull. 42: 179-190. Illinois St. Lab. Nat. Hist. 10: 274-544. Simpson, K. W. and R. W. Bode 1980 Common Mason, W. T, Jr. and J. E. Sublette 1971 larvae of Chironomidae (Diptera) from New York Collecting Ohio River Basin Chironomidae (Dip- State streams and rivers, with particular reference tera) with a floating sticky trap. Can. Entomol. to the fauna of artificial substrates. New York St. 103: 397-404. Mus. Bull. 439: 1-105. Menzie, C. A. 1980 The chironomid (Insecta: Sublette, J. E. 1957 The ecology of the macro- Diptera) and other fauna of a Myriophyllum scopic bottom fauna in Lake Texoma (Denison apicatum L. plant bed in the lower Hudson River. Reservoir), Oklahoma and Texas. Amer. Midland Estuaries 3: 38-54. Nat. 57: 371-402. Oliver, D. R. 1977 Bicinctus-group of the genus 1964 Chironomidae (Diptera) of Cricotopus Van der Wulp (Diptera: Chironomidae) Louisiana I. Systematics and immature stages of in the Nearctic with a description of a new species. some lentic chironomids of west-central J. Fish. Res. Bd. Canada 34: 98-104. Louisiana. Tulane Stud. Zool. 11: 109-150. Paine, G. H., Jr. and A. R. Gaufin 1956 1966 Type specimens of Chirono- Aquatic Diptera as indicators of pollution in a midae (Diptera) in the US National Museum. J. midwestern stream. OhioJ. Sci. 56: 291-304. Kansas Entomol. Soc. 39: 580-607. Roback, S. S. 1957 The immature tendipedids 1967 Type specimens of Chirono- of the Philadelphia area (Diptera: Tendipedidae). midae (Diptera) in the Cornell University collec- Monogr. Acad. Nat. Sci. Philadelphia 9: 1-152. tion. J. Kansas Entomol. Soc. 40: 477—564. 1962 Some new Tendipedidae from 1970 Type specimens of Chirono- the Canal Zone. Notulae Naturae, No. 355: midae (Diptera) in the Illinois Natural History 1-10. Survey Collection, Urbana. J. Kansas Entomol. Rosenberg, D. M. and A. P. Wiens 1976 Com- Soc. 43: 44-95. munity and species responses of Chironomidae and M. S. Sublette 1965 Family Chi- (Diptera) to contamination of fresh waters by ronomidae (Tendipedidae). USDA Agri. Hand- crude oil and petroleum products, with special book 276: 142-181. reference to the Trail River, Northwest Territories. Surber, E. W. 1959 Cricotopus bicinctus, a J. Fish. Res. Bd. Canada 33: 1955-1963. midgefly resistant to electroplating wastes. Trans. , and O. A. Saether Amer. Fish. Soc. 88: 111-116. 1977a Life histories of Cricotopus (Cricotopus) Tucker, E. S. 1907 Some results of desultory col- bicinctus and C. (C.) mackenziensis (Diptera: lecting of insects in Kansas and Colorado. Kansas Chironomidae) in the Fort Simpson area, North- Univ. Sci. Bull. 4: 51-108. west Territories. J. Fish. Res. Bd. Canada Winner, R. W., M. W. Boesel and M. P. Farrell 34: 247-253. 1980 Insect community structure as an index , and 1977b Re- of heavy-metal pollution in lotic ecosystems. sponses to crude oil contamination by Cricotopus Canadian J. Fish. Aquat. Sci. 37: 647-655. (Cricotopus) bicinctus and C. (C.) mackenziensisWirth, W. W. 1957 The species of Cricotopus (Diptera: Chironomidae) in the Fort Simpson midges living in the blue-green alga Nostoc in area, Northwest Territories. J. Fish. Res. Bd. California (Diptera: Tendipedidae). Pan-Pac. Canada 34: 254-261. Entomol. 33: 121-126.

EDITOR'S NOTE The backlog of manuscripts has now been reduced to the extent that new papers can appear in The Ohio Journal of Science less than 12 months after acceptance.