Achelipoda tumida, Plant, Adrian R., 2009

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 : 46-47

6. Achelipoda tumida sp. n.

[ Figs. 5, 7 –9]

Type material. Holotype 3: Singapore, Nee Soon, swamp forest, Malaise trap, 4.xii.2002, P. Grootaert [ IRSNB]. Paratypes: 3Ƥ, same data as holotype, 4.xii.2002, 3.iii.2006, 3.xii.2003; 9Ƥ, Sime Forest, Malaise trap 17.ii.2006, 19.v.2005, 6.v.2005, 19.viii.2005, 7.ix.2005, 16.ix.2005, 18.xi.2005, 3.xii.2005 [ ZRC, IRSNB, NMWC]. Holotype deposited in ZRC.

Etymology. The specific epithet derives from ‘tumidus’ (Latin) meaning ‘swollen’ or ‘inflated’ in reference to the swollen hind tibia in the female of this species.

Diagnosis. A yellowish species with wings faintly infuscated but apically clear in female. Female with hind tibia inflated and with a distinct posteroapical spur. Male distinguished from A. kanaklua primarily by form of the genitalia.

Description. Male: length 2.5 mm. The holotype male appears to have become partially bleached during preservation and colour may be darker in life than in following description. It is also somewhat damaged with antennal stylus broken and most thoracic and head setae detached.

Head: dark brown with antenna and mouthparts (including palpus) brownish yellow.

Thorax: orange-brown with only a vaguely darker patch on katepisternum ventrally behind base of C1.

Legs: yellow, faintly darker on apical tarsomeres. C1 0.9X as long as thorax, hardly narrowed distally. F1 as long as C1, inflated ventrally with usual double row of spines and denticles beneath; basal spines of av and pv series almost as long as F1 is deep, yellow; basal spine distinct. C3 not inflated, similar in size as C2.

Abdomem: brownish yellow, bare apart from a few small setae on sternite 7 ventrally. Hypandrium + epandrium ( Fig. 5 ) narrowed posteriorly, yellow. Anterior lobe of cercus flattened, brownish, with ‘fan’ of strong yellowish setae and sharply pointed, black anteriorly direct process ( Fig. 5 ); median lobe yellowish with two distinct setae. Phallus yellow, long, very evenly curved anteriorly. Subepandrial process yellow, bent at right angle distally.

Wing: veins yellowish brown, membrane faintly tinged yellowish, without banding pattern and not obviously clear apically. Wings with crossveins closing cells bm and br almost strictly aligned, cell br equal to in length to cell bm; vein CuA2 reaching wing margin.

Description. Female: similar to male, differing as follows.

Head: black with antenna and mouthparts brownish. Ocellar, vertical and postocular setae rather well developed, blackish; lower occipital pile pale and fine. Antenna with postpedicel 3–3.5X as long as wide, stylus 1.5X as long.

Thorax: orange-brown; dark patch behind C1 darker than in male but not strongly defined; dorsocentrals rather stronger than in A. pictipennis but sa clearly strongest seta on the thorax.

Legs: Femoral formula approximately 5/21/18 /5 +1 with basal spine and 2–3 spines of av and pv series basally as long as limb is deep. T3 as narrow as T2 basally but considerably inflated on distal 0.5 where distinctly wider than T2 (Fig. 9), bearing a distinct black posteroapical spur.

Abdomen: almost bare, pale brown with terminal segments bearing a few longer hairs laterally and cercus darker still with longer hairs. Sternite 8 viewed from below with conspicuous U-shaped darker brown sclerotization.

Wing: similar to male but membrane indistinctly clear at extreme apex.

Comment. Achelipoda tumida is recorded only from moist forest biotopes in Singapore. Adults have been collected between February and September and in December.

Figures

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.