The Larvae of Chauliodes Latreille (Megaloptera: Corydalidae)'
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THE LARVAE OF CHAULIODES LATREILLE (MEGALOPTERA: CORYDALIDAE)' R. DUNCAN CUYLER ABSTRACT Larvae of Chauliodes differ from those of other North of inequality and the length of the tubules, and by the American genera of Megaloptera hy having the spiracles color of the prothoracic and atjdominal dorsum. Larvae of the 8th abdominal segment at the ends of two unequal, of Chauliodinae and of Coiydalis are compared, generic elorgated tubules. The larvae of the two Nearctic larval characters of Chn~~liodesare given, and larvae of species, C. mst~icornisand C. pectinicounis, have been the two species are described from material collected confused in the past but can he separated 5y the degree in North Carolina. The family Corydalidae is divided into the insure against disfiguration when subsequently subfamilies Corydalinae and Chauliodinae. Prior placed in alcohol. to 1908, all species of Chauliodinae were included The initial identification of the Chauliodes in the genus Chauliodes Latreille 1807. The five larvae collected by the writer was based on the genera of Chauliodinae now recognized in the following circumstances. Certain larvae pos- Nearctic region are Chauliodes, Dismycohermes sessed markings on the prothorax and abdomen Munroe 1953, Protochauliodes Van der Weele 1909, which were identical with markings on those Neohermes Banks 1908, and Nigronia Banks 1908. body parts of Chauliodes pectinicornis adults. Chauliodes contains two North American species, This finding indicated that these larvae also were C. rastricornis Rambur and C. pectinicornis pectinicornis, and that the larva of this species (Linnaeus), both of which are largely restricted can be identified by means of a yellow stripe on to the eastern United States. As a result of a the middorsum of the prothorax and abdomen. number of inconsistencies found in the literature, It was noted also that other chauliodine larvae, the true identities of the larvae of these two collected prior to the pectinicor-rzis larvae, pos- species have not been established heretofore. sessed a black middorsal stripe on the thorax and Table 1.-Differences between larvae of Corydnlis and of Chauliodinae -- I Structure 1 Corydalis 1 Chauliodinae Labrum ............... elongate (fig 4) transverse (fig. 7) Lateral margin of gena . strongly angulate (fig 4) ! convex or ireakly angulaie ( (fig. 7), except in Dis- mycohe~jnzes Mandibles. ................. symmetrical (fig. 4) asymmetrical (fig. i) Antennae .................. 5-segmented 4-segmented Lateral filaments.. ....... carinate; tufted with hairs not carinate: not tufted with on abdominal segments hairs on abdominal seg- 1-8 (fig. 6) ments 1-8 (fig. 8) Spiracles.. ...................~ cribriform annular Tufts of tracheal gills on abdominal venter........... .I present (fig. 6) absent (fig. 8) Spiracles of 8th abdominal I segment .....................I near base of lateral filament at posterior margin of segment (fig. 8) (fig. lo), or at end of respira- tory tube (Chnulzoder, fig. 9) Hydrofuge hairs on 9th ad- dominal ventrite. ........... present absent Clarate macro- and microsetae present absent I Larvae and pupae of various Chauliodinae, abdomen. Subsequently, when the first of the including both species of Chauliodes, were col- pectinicornis larvae was collected, it was apparent lected by the writer in east-central North Caro- that a different species of larva had been taken. lina, chiefly in Durham, Wake, and Orange When it was determined that this second larva Counties. Attempts were made on a number of belonged to pectinicornis, it was suspected that occasions to rear the immature forms. No larvae specimens of the other species belonged to were reared from ova, but several of the larvae rastricor~zis.Both species possessed caudal respira- and pupae completed their development to the tory tubes (tubes subtending the spiracles of the adult stage. Other larvae were placed in KAAD eighth abdominal segment), indicating that they solution or boiled to coagulate the proteins and were congeneric. Later, a preserved pupa of rastricornis was 'Accepted for publication April 28, 1958. examined. It possessed a dark middorsal stripe e 19581 Cuyler : Larvae of Chauliodes 583 on the abdomen, as do larvae of this species. larvae of this subfamily and those of the Coryd- Still later, a large number of pupae of this species, alinae, as represented by the very well-known as well as larvae preparing to pupate, were col- Corydalis corlzuta (figs. 1, 4, 5, 6). In the lected. Two adults, a male and a female, were Chauliodinae the left mandible bears an addi- reared from pupae; and three males and three tional tooth apical to the three regular teeth. females were reared from larvae. All of these Larvae of the genus Dismycohermes are excep- adults, and a number of adults subsequentlv tional in the Chauliodinae in that the gena is collected, possessed abdominal markings like strongly angulate, as it is in Corydalis. those of the larvae and pupae. Genus Chauliodes DESCRIPTIONS Larvae of this genus may be recognized im- The descriptions presented here are based mediately by the presence of a pair of long, chiefly upon larvae more than 25 millimeters in unequal tubules bearing the spiracles of the length. It happens that some specimens may be eighth abdominal segment. stretched more than others by the KAAD Prothorax quadrangular, approximately 1M solution. Consequently, two preserved speci- times broader than long; lateral filaments narrow, mens which are apparently of the same length nearly threadlike in appearance; spiracles of may not have been of the same size originally. abdominal segments 1 to 7 located slightly anterior to level of bases of lateral filaments, SUBFAMILYCHAULIODJNAE nearly sessile; spiracles of segment 8 located at Table I sets forth the major differences between ends of long respiratory tubes arising close to- FIG. 1.-Corydalis coinuta (Linnaeus). Preserved specimen from Little Creek, Orange County, North Carolina, March 10, 1956. Natural size. FIG. 2.-Clzauliodes rastricoinis Rambur. Living specimen from Anerican Legion Pond, Fuquay-Varina, North Carolina, March 29, 1956. Enlarged x1.5. FIG.3.-Chaw liodes peciinicoinis (Linnaeus). Preserved specimen from swamp, Durham County, North Carolina, August 16, 1953. Enlarged x2.3. 5 84 Annals Entomological ' Society of America lITol.51 gether from posterior margin (fig. 9) ; respiratory dorsal stripes, submedian vertical streaks, and tubes unequal, the longer one on either left or irregular brown lateral areas ; legs yellowish ; right; hairs longest on abdomen, irregular in abdomen yellowish gray mottled with brown, with length on lateral margin of head; abdomen and middorsal brom71l streak 0.5 mm, wide and with a lateral filaments with small papillae scattered thinly over surface; legs with spines. Habitat.-Lenitic bodies of water, including lakes, ponds, and swamps; pupation chiefly in decaying logs or stumps above water level or on adjacent land. Epis fomal Suture --------- -- ~ntenniferou5Tubercle KEY TO LARVAE OF CH.4ULIODES F~~~~ --- Pleurostomal Suture Fronta/ Longer respiratory tube as long as combined length of Suture abdominal segments 6 to 8 or 5 to 8. shorter tube Gens ----------I Sio to $6 as long as longer one; abdomen with black mid- dorsal stripe. .........................C. rastricornis Longer respiratory tube as long as combined length of abdominal segments 7 and 8, shorter tube ?$ to 45 as long as longer one; abdomen with yellow middorsal stripe. ...............................C. pectinicornis Chauliodes rastricornis Rambur Flgure 2 , I cm. , Lafera/ FjIarnen+ Length 34.0 mm. ; head 5.5 mm. wide; occipital suture convex, sinuate, not concave middorsally; pronotum 4.3 mm. long, 5.73 mm. wide; first abdominal segment slightly more than twice as wide as long; proleg 1.15 mm. long, claws 0.35 mm. ; lateral filament of first abdominal segment as long as width of segment, filament of eighth segment 2% times longer than width of segment, filament of proleg surpassing claws by length of claws; spiracles 0.15 mm. in diameter; longer respiratory tube as long as combined length of segments 5 to 8 or G to 8 (8.0 mm.); shorter L----~rocheal respiratory tube 0.3 to 0 67 length of longer I cm. tube; hairs longer than those of C. pectinicornis, 1 Gill5 those of lateral filaments distinctly longer than 6 basal diameter of filament. Labrum reddish brown; clypeus yellow; frons and vertex brown, obscurely phalerate with reddish and with tawny streaks immediately mesad of lateral margin; occiput reddish brown with minute dorsolateral black streak; prothorax tawny, mottled with black and brown and with dark brown middorsal stripe 0.2 mm. wide at top and abruptly narrowing to 0.1 mm.; meso- and metathorax tawny, with dark brown mid- FIG. 4.-Corydalis cornuta. Dorsal viem- of head. (Line draxving by Louise Horne, Mt. Zion Hospital, San Francisco, California.) FIG. 5.-Corydalis covnuta. Caudal end of abdomen, dorsal view. (Line drawing by Louise Horne.) FIG. 6.--Co~ydalis cornuta. \-enter of first and second abdominal somites. (Line drawing bv- 1,ouise Horne.) FIG. 7.-Chauliodes pectinicounis. Dorsal view of head. (Line draw-ing by Department of Medical Art and Illustration, Duke Hospital, Durham, North Carolina.) FIG.8.-Chazrliodes pectinzcoun,is. Venter of first and secona abdominal somites. (Line drawing by Depart- ment of Medical Art and Illustration, Duke Hospital.) 19.581 Cuyler: Larvae of Chauliodes 585 somewhat narrower line one-third the distance rastricorlzis. His description was more