Achelipoda Yang, Zhang & Zhang, 2007

Plant, Adrian R., 2009, Revision of the east Asian genus Achelipoda Yang, Zhang & Zhang, 2007 (Diptera: Empididae: Hemerodromiinae) including designation of a neotype for Achelipoda pictipennis (Bezzi, 1912) and descriptions of six new species, Zootaxa 2020, pp. 37-50 : 38-39

Genus Achelipoda Yang, Zhang & Zhang, 2007

Achelipoda Yang, Zhang & Zhang in Yang, Zhang, Yao & Zhang, 2007: 22. Type species Chelipoda pictipennis Bezzi, 1912: 476 , by original designation.

Diagnosis. A characteristic genus of the empididine subfamily Hemerodromiinae with raptorial forelegs, distinctly separated from the midlegs (Fig. 9) and with the fore femur bearing distinct rows of stout setae ventrally. Achelipoda is distinguished from other Hemerodromiinae by the combination of (1) basal cells br and bm more or less exactly equal in length (2) anal vein absent, and (3) vein CuA2 extending to (or almost to) posterior margin of the wing (Figs. 9–11).

Description. Head: subspherical, slightly dorsoventrally flattened with eyes widely separated on frons, almost touching below antennae on face in both sexes. Ocellar area slightly protuberant with a pair of small setae. A pair of verticals present, merging more or less contiguously with line of post ocular setae. Lower occiput with fine pile. Antenna with postpedicel distinctly short-pilose, pointed lanceolate with stylus longer (at least 1.5 X as long). Stylus minutely pilose with very short basal article bare. Scape with a distinct but usually small dorsal seta. Pedicel with circlet of setae longest on exterior face. Mouthparts with proboscis short and pointed, downwardly directed. Palpus small, elongate, bearing a distinct long apical and a few smaller subapical setae.

Thorax: rather short; scutum rounded quadrate in dorsal view, only 1.20–1.25 X as long as wide at notopleural suture. Humeri virtually undeveloped. Thoracic setae generally short and inconspicuous. Scutum with only supraalar seta strongly developed. Usually 4–5 pairs of dc, longest in front (anterior dc in line with humeral area). A pair of minute npl present or absent. No humeral (postpronotal), posthumeral or acrostichal setae present. Scutellum with a pair of short fine incurved terminal setae. Laterotergite with 2 –4 very fine and inconspicuous setulae.

Legs: with C1 almost as long as thorax, C2 and C3 much shorter but C3 sometimes rather inflated and somewhat ellipsoid in profile. Front femur inflated, much stouter than other femora; about as long as front coxa; armed ventrally with a double row of minute tooth-like denticles, either side of which is a row of ‘normal’ spine-like setae which are longest basally and often inconspicuous or absent distally. One or two longish setae basally to, and usually slightly discontiguous with the major quadruple rows of setae. Front tibia distinctly geniculate basally, shorter than front femur, bearing a single row of minute adpressed denticles ventrally which when the limb is reflexed articulate against the corresponding double row on the front femur. Mid and hind femora simple, only slightly inflated with their corresponding tibiae very slender and lacking strong setae but hind tibia of female sometimes slightly inflated or with a distinct posteroapical spur.

Wing: narrow basally with axillary angle hardly developed. Vein C circumambient but weak beyond tip of R4+5. Sc complete but usually weak apically. R1 rather short but joining C beyond end of basal cells. Radiocubital praefurca short, usually weak at extreme base where curved up to join R1. Cells br and bm more or less exactly equal in length, quadrate apically with crossveins r-m and bm-cu in line or nearly so; br never noticeably longer or narrower than bm and bm not produced posteroapically. Vein M weak basally between br and bm, stronger distally with two branches. Crossvein dm-cu absent (cell dm absent). Anal vein absent, CuA2 usually extending to (or almost to) posterior margin but occasionally abbreviated ( A. kharkhema sp. n.). Marginal cilia short along costa, longer on posterior margin. Membrane often pigmented or with banded pattern, stigma absent. Costal seta present.

Male Abdomen: with tergites 2 – 6 regularly broad, tergites 7 and 8 much narrower. All segments usually sparsely haired but tergite 5 sometimes with a ‘fan’ of stronger setae posterodorsally. Hypandrium and epandrium completely fused, keel-like ( Figs. 1–6 ), as broad or broader than preceding segments of abdomen, without any indication of a median membranous region ventrally. Only apex of strongly anteriorly directed phallus and subepandrial process emerging from an anterodorsal or dorsal opening between the fused epandrium + hypandrium which otherwise completely enclose the genitalia. The cerci are here interpreted as completely fused along anterodorsal or dorsal margin of the epandrium; consisting of a median and anterior lobe ( Fig. 2 ) connected by a long narrow darkened rim fused with the dorsal margin of epandrium to a posterior lobe which forms a slightly raised ‘lip’ posterodorsally above apex of epandrium. However it is possible that the median and posterior lobes are merely an anterodorsal and posterodorsal productions of the epandrial margin respectively. The median lobe is rather rounded bearing long fine setae which often curve inwardly, overlapping the recurved distal parts of the phallus and subepandrial process. The anterior lobe is free, more or less triangular, projecting anteriorly (often considerably so), bearing numerous apical setae.

Phallus and subepandrial process anteriorly reflexed basally, often narrow, their distal sections lying just above cercus and extending at least as far forward as the apex of its anterior lobe.

Female abdomen: with cercus moderately elongate and bearing distinct fine setae.

Figures

FIGURES 1 – 4. 3 genitalia of Achelipoda spp., lateral view. 1. Achelipoda kharkhema sp. n. 2. Achelipoda kanaklua sp. n. 3. Achelipoda pictipennis (Bezzi). 4. Achelipoda subobscura sp. n. Abbreviations: cal, anterior lobe of cercus; cml, median lobe of cercus; ej apod, ejaculatory apodeme; go apod, gonocoxal apodeme; ph, phallus; subep, subepandrial process.

FIGURES 5 – 8. Genitalia of Achelipoda spp. 5 – 6. 3 genitalia, lateral view. 5. Achelipoda tumida sp. n. 6. Achelipoda vietnamensis sp. n. 7 – 8. Achelipoda tumida sp. n. Ƥ genitalia. 7. lateral view. 8. ventral view.