Campsicnemus plautus Evenhuis

Evenhuis, Neal L., 2009, Review of Campsicnemus (Diptera: Dolichopodidae) of the Marquesas, French Polynesia, with description of four new species groups, Zootaxa 2004, pp. 25-48 : 38-39

Campsicnemus plautus Evenhuis , new species

( Figs. 7 , 16 )

Diagnosis. Most similar in appearance to C. englundi , n. sp. from Fatu Hiva but can be distinguished from it by the flared mid basitarsus (mid basitarsus thick but cylindrical apically in C. englundi ) and the uniform length of the setae on the anterior surface of the mid tibia (these setae scattered and long in C. englundi ).

Description. Male. Body length: 2.4 mm. Wing length: 2.6 mm.

Head. Black, face dark brown to black with reddish highlights, paler brown near clypeus; oc and vt black, about one-third length of antennal arista; front, occiput, and vertex black with blue highlights; face constricted at middle, almost holoptic, eyes separated below antennae by width of 1–2 ommatidia; palp small, dark brown; proboscis brown, extending below eye in lateral view; antennal segments black to brown; postpedicel conical, length about 1.5 x width; arista slightly longer than head height.

Thorax: Mesoscutum, scutellum, and pleura dark brown to black throughout, with a few metallic bluish highlights laterally; thoracic setae black: 1 + 4 dc; 2 np; 2 ph; 1 pa; 1 + 1 sc; ac absent; halter stem white, knob dark brownish black.

Legs: CI yellowish; remainder of legs (except yellow venter of basal three-fourths of FI) brown; foreleg unmodified, without MSSC; FII ( Fig. 16 ) with strong, swollen area ventrally bearing rows of strong, stiff black setae ventrally, single long black seta subbasally; with prominent protuberance on apical one-third bearing strong thick black seta and small patch of finer setae, apex of FII with 3 strong black setae; FIII as in C. gladiator , with row of long setae on ventroapical surface and with row of long hairs on dorsoapical twothirds (MSSC); TiII ( Fig. 16 ) slightly swollen on apical three-fourths, thickest at middle, with row of stiff black setae on subbasal third on mesal surface, sparse stiff black setae on apical two-thirds of lateral surface (MSSC). TiIII with dense patch of strong stiff setae subbasoventrally, slightly curved apically, becoming shorter apically, dorsal surface with small hairs and only two long setae (one subbasally; the other near middle) (MSSC). IIt1 ( Fig. 14 ) slightly longer than IIt2, distinctly flared apically, with row of small spicules dorsolaterally and short fine hairs ventrally; IIt2 broad, rounded, subcylindrical, inserted apically on IIt1, with row of stiff fine hairs ventrally. Remainder of leg segments without MSSC.

Wing: pale smoky throughout; posterior crossvein perpendicular to vein M.

Abdomen. Brown with short black hairs dorsally on each tergite, a few longer hairs laterally; tergal interstices whitish; sternites pale brown. Hypopygium brown with paler brown cerci, not dissected.

Female. Unknown.

Types. Holotype ɗ (BPBM Type 16,639) [BPBM 101252] from FRENCH POLYNESIA: Marquesas: HIVA OA: Upper Atuona Valley, Atikoua stream, 340 ft [103 m], 12 Aug 2001, splash zone, R.A. Englund (see Fig. 7 ). Holotype in BPBM.

Etymology. The specific epithet derives from the Latin plautus = broad, flat; referring to the relatively broad, flat, flared mid basitarsus of the male.

Figures

FIGURES 7 – 9. Marquesan habitats. 7. Hiva Oa, Upper Atuona Valley, Atikoua Stream: type locality for Campsicnemus plautus, n. sp. and habitat for C. uncleremus Evenhuis. Collector Dan Polhemus in foreground. 8. Nuku Hiva, Hakaui River: probable type locality for C. scurra Parent. 9. Ua Huka, Hitikau Ridge. Inset: collector Dan Polhemus fogging on ridge summit: habitat for C. uu, n. sp.

FIGURES 14 – 16. Campsicnemus englundi group, male midlegs. 14. C. cheesmanae, n. sp., femur, tibia, and basitarsus. 15. Campsicnemus englundi, n. sp., femur, tibia, and basitarsus. 16. Campsicnemus plautus, n. sp., femur, tibia, and all tarsi, showing flared basitarsus and swollen second tarsomere.