Camptochaeta chilkatensis, Vilkamaa & Menzel, 2017

Vilkamaa, Pekka & Menzel, Frank, 2017, Descriptions of new species of the genera Camptochaeta Hippa & Vilkamaa and Corynoptera Winnertz (Diptera, Sciaridae) from the Holarctic, Zootaxa 4353 (2), pp. 347-359 : 348-349

Camptochaeta chilkatensis sp. n.

Fig. 1 A, B

Material studied. Holotype male . USA, Alaska, Haines, Chilkat State Park, Battery Point Trail , 59.216137°N, 135.391700°W, 20.V.2016, S. Fitzgerald (in MZH). Paratypes . Same data as holotype, 4 males (2 in MZH, 2 in SDEI).

Description. Male. Head. Face and antenna concolorous brown, maxillary palpus very pale brown. Eye bridge 2–3 facets wide. Face with 4–8 scattered longer and shorter setae. Clypeus with 1–2 dark setae. Maxillary palpus with 3 segments; 3rd segment longer than 1 st segment , 2nd segment shortest; 1 st segment with 1–3 long sharp setae, with an irregular shallow pit bearing sensilla; body of 4th antennal flagellomere 3.8x as long as wide, surface smooth, neck slightly shorter than broad, the longest setae longer than width of flagellomere. Thorax. Dark brown, setae dark. Anterior pronotum with 6–7 setae. Proepisternum with 8–11 setae. Wing. Fumose. Length 2.6–2.7 mm. Width/length 0.40–0.45. Anal lobe moderate. R1/R 1.0–1.1. c/w 0.80. Veins distinct; stM slightly shorter than fork of M, bM as long as r-m, r-m with 2–5 dorsal setae, bM non-setose. Halter pale brown. Legs. Pale brown. Coxal setae dark. Fore tibial organ with dark vestiture in large demarcated patch in depression. Fore tibial spur longer than the tibial width. Abdomen. Pale brown, setae dark and rather long and strong. Hypopygium ( Fig. 1 A ). Brown, concolorous with abdomen. Gonocoxa longer than gonostylus, gonocoxae separated, with rather short medial setosity. Gonostylus ( Fig. 1 B ) strongly narrowed apically, with the ventromedial side strongly impressed; apicomesially with a few elongated setae; with strong apical tooth, with a megaseta on the dorsal side of apical tooth, 1 megaseta subapical on the ventral side of the base of tooth and one megaseta slightly more basal; megasetae subequal in length, nearly straight, shorter than apical tooth, without basal bodies; a flagellate seta at middle of gonostylus. Tegmen subtriangular, with sublateral sclerotized stripes on the apical half, with an area of distinct aedeagal teeth. Aedeagal apodeme rather strong.

Discussion. The gonostyli of Camptochaeta chilkatensis sp. n., C. curtipilosa sp. n., C. fitzgeraldi sp. n. and C. fulvistylata sp. n. are very similar to each other, in having one megaseta just on the lateral side of the apical tooth, one on the ventral side of the tooth, and one subapically at or near the medial margin of the gonostylus. All species have a subtriangular tegmen with sublateral sclerotizations. In these characters they resemble Camptochaeta winchesteri Vilkamaa, Hippa & Heller, 2013 from British Columbia, but this species has longer megasetae and a longer and narrower apical tooth of the gonostylus. Camptochaeta chilkatensis and C. fitzgeraldi differ from the other two new species in having the setae of coxae, abdomen and hypopygium dark, whereas C. curtipilosa and C. fulvistylata have pale setae. Furthermore, Camptochaeta chilkatensis and C. fitzgeraldi lack distinct basal bodies in the subapical megasetae, which are present in the other two species.

Camptochaeta chilkatensis can be distinguished from C. fitzgeraldi by its relatively wider gonostylus with a more pronounced dorsomedial margin, in having a stronger apical tooth, and by its apically narrower tegmen. Camptochaeta chilkatensis is also larger (wing length 2.6–2.7 mm versus 2.2 mm).

Etymology. The species is named after the type locality, the Chilkat River in Alaska.

Figures

FIGURE 1. Camptochaeta chilkatensis sp. n. (holotype). A. Part of hypopygium, ventral. B. Gonostylus, ventral. Scale 0.10 mm.