Leptopezella Sinclair & Cumming

Sinclair, Bradley J. & Cumming, Jeffrey M., 2007, Leptopezella, a new Southern Hemisphere genus of Ocydromiinae (Diptera: Empidoidea: Hybotidae), Zootaxa 1629, pp. 27-37 : 28-30

Leptopezella Sinclair & Cumming , gen. nov.

Leptopezella Sinclair & Cumming 2006: 78 , nomen nudum.

Type species: Leptopezella spinosa , sp. nov.

Diagnosis: This genus is easily separated from all other ocydromiine genera by the absence of crossvein dm-cu and cell dm, M vein evanescent, wing very slender with anal lobe not developed, and hind first tarsomere with spine-like ventral setae.

Description. Wing length 2.2–2.7 mm.

Male ( Fig. 1 ). Head dark, with extensive tomentum. Eye bare, dichoptic above, closely approximated immediately below antenna to just above mouthparts; anterior facets between antennae and mouthparts enlarged. Frons slightly divergent to nearly parallel-sided. Gena not extended below eye; postgena with sparse fine setae. One pair of ocellar bristles, directed forward. One pair of postocellar, 1 pair of vertical and 1–2 pairs of upper occipital setae. Antennae ( Fig. 4 ) inserted above middle of head; scape slightly shorter than pedicel in length, scape devoid of setulae; pedicel cylindrical, with circlet of short preapical setulae; postpedicel elongate-ovate. Stylus arista-like, arising apicodorsally, longer than basal three segments; clothed in fine pubescence; apex with long, slender bristle-like mechanoreceptor (= segment 10 or apical style). Mouthparts ( Fig. 5 ) small, not stout; length of proboscis less than one-quarter height of head; palpus short-ovate, flattened and slightly pointed apically; pale, two-thirds length of exposed proboscis with several prominent setae; labrum not recurved; hypopharynx arched gently on apical fourth; labellum weakly sclerotized, clothed in two rows of setulae; more than 10 pseudotracheae present; prementum thickly sclerotized laterally, membranous medially.

Thorax polished or finely clothed in tomentum; light to dark brown in colour, hunch-backed, postpronotal lobe and postalar callus well developed; prosternum separate from proepisternum; antepronotum well-developed. Thoracic macrotrichia mostly slender and short; acrostichal setulae uni- to biserial extending beyond transverse suture; dc uniserial; npl, pal and apical sctl long and strong. Meso- and metapleuron generally clothed in tomentum.

Wing ( Fig. 2 ) hyaline, anal lobe not developed; short, only slightly longer than body; microtrichia uniform, clothed throughout; costal setae short; basal costal seta reduced; costa fading beyond R4+5; Sc evanescent, extending to beyond branching of R2+3 and R4+5; stigma very slender at apex of cell r1; Rs short, arising near apical third of cell bm; cell dm absent; M vein unbranched, very weak, wavy and evanescent; cell bm pointed apically; M4 (CuA1) arched to wing margin; cell cua (cell cu p or anal cell) two-thirds length of cell bm; CuA straight, strongly directed obliquely to base of wing; CuP+CuA (A1) vein reduced, nearly equal in length of cell cua, not reaching wing margin ( Fig. 2 ). Halter pale with whitish knob.

Legs pale proximally, darker distally, especially hindleg. Fore and midlegs much shorter and more slender than hindleg. Fore tibial gland present, occasionally expanded in male. Fore tibial anteroapical comb small. Hind femur slightly expanded apically; hind tibia clavate, strongly expanded, with large posteroapical comb. Hind tarsomeres expanded compared to other legs; tarsomere 1 at least half width of apex of hind tibia, bearing 1–2 rows of often black spine-like ventral setae ( Fig. 3 ).

Abdomen. Tergites generally well sclerotized, often darkly polished; sternites less sclerotized, generally paler. Sclerites of segment 8 not fused, tergite 8 approximately one-half to three-quarters length of tergite 7. Hypopygium asymmetrical, rotated approximately 45° to right. Hypandrium short and quadrate to elongate and produced apically; dorsal bridge straight. Epandrium deeply cleft, asymmetrical; left epandrial lamella usually with large spine-like seta at apex (many Australian species); surstyli asymmetrical, fully articulated. Bacilliform sclerites long and generally slender, bearing several setae. Cercus unmodified, short, slender and thinly sclerotized. Hypoproct often produced distally into asymmetrical hook-shaped process. Phallic shaft long, gradually arched, cylindrical, bearing long, spiralling, spinous, membranous distiphallus; ejaculatory apodeme rod-shaped, fused to base of phallus.

Female. Similar to male including head and legs except as follows: abdominal tergites 1 and 2 not fused; segments 1–7 broad, segments 2–6 nearly two times wider than long, width and length of segment 7 subequal; terminal segments partially retracted into 7th (in dried specimens). Segment 8 four times longer than wide; tergite 8 longitudinally divided medially into 2 long slender sclerites, more weakly sclerotized distally; sternite 8 undivided medially; tergite 10 divided medially, widely separated and half length of sternite 10. Cercus long and very slender, slightly less than half length of tergite 8; well sclerotized, bearing long scattered setae ( Fig. 6 ).

Distribution and habitat. This genus is confined to South America ( Bolivia, Argentina) and eastern and western Australia and apparently prefers moist or damp forest undergrowth. Specimens in Australia were swept from the under-story in wet sclerophyll and gallery rainforests in the Blue Mountains, temperate rainforests in Tasmania, the Otway Ranges (Victoria) and Border Ranges (Brindle Creek, New South Wales), and wet sclerophyll forests in Western Australia (Nornalup). In Bolivia, numerous specimens were swept from primary cloud forest at nearly 2000 m.

Figures

FIGURE 1. Leptopezella perata, sp. nov., habitus, lateral view. Scale bar = 1 mm.

FIGURES 4 – 8. Antenna, mouthparts, female and male terminalia. 4. Leptopezella perata, sp. nov., antenna, lateral view. 5. L. perata, sp. nov., mouthparts, lateral view. 6. L. perata, sp. nov., female terminalia, lateral view. 7. L. anatolica, sp. nov., male terminalia, dorsal view with phallus removed. 8. L. anatolica, sp. nov., male terminalia, left lateral view. Abbreviations: cerc – cercus; distph – distiphallus; ej apod – ejaculatory apodeme; epand – epandrium; hypd – hypandrium; hyprct – hypoproct; sur – surstylus; st – sternite; tg – tergite. Scale bar = 0.1 mm.

FIGURES 2 – 3. Leptopezella perata, sp. nov. 2. Wing. 3. Hind leg. Abbreviation: tm 1 – first tarsomere. Scale bar = 0.5 mm.