Ewaurista pusilla, Shcherbakov & Azar, 2019

Shcherbakov, Dmitry E. & Azar, Dany, 2019, A new subfamily of Trichoceridae (Diptera: Tipulomorpha) from Early Cretaceous Lebanese amber, Zootaxa 4563 (2), pp. 311-324 : 313-314

Ewaurista pusilla sp. nov.

Material. Holotype male, no. 264; Lebanese amber, Early Barremian; Hammana Mdeirij outcrop. Paratypes: males, nos. 88, 204a, 336 (head missing), 436d, 517, 611, 771d, 1038, 1120a, 1243b (wings and abdomen missing, sex determined by antenna structure); females, nos. 296, 332, 467, 1151d, 204b (in same piece of amber as, and close to, male no. 204a; fragmented, abdomen missing, sex determined by wing and leg structure), 1120b (in same piece of amber as, and close to, male no. 1120a); Lebanese amber, Early Barremian; Hammana Mdeirij outcrop.

Description ( Figs. 1–21 ). Ocellar tubercle with median depression; ocelli three, small. Ommatidia quite large (about 10 rows across the eye), without hairs in between. Antennae of 18(?) segments (segmentation obscure distally). Pedicel enlarged, almost 1/3 (female) or 1/2 (male) eye diameter. 1st flagellomere largest, almost twice wider and 1.5 times longer than next one. Palps shorter than head capsule, of four free segments (not counting very short basal piece), first longest, two last ones of subequal length, terminal one neither elongated (as in Cladoneura ) nor constricted (as in some Trichocera spp.). Labium small. Mesonotum with about 5 dark setae on each side; scutellum with pair of apical setae. Femora slightly clavate. Tibiae and tarsi covered with suberect setae, femora (especially towards base) more sparsely so. Legs (especially tarsi) and abdomen more slender in male. Male claws and last tarsomeres not strongly differing from those of female. Ratio of wing length to its maximal width 2.9–3.1 in both sexes; pterostigma more pigmented in male. Sc ending distad of Rs and M bifurcations (male) or about midlength of Rs stem (female). Rs originating nearer to M bifurcation than to basal R bend. Male abdomen dorsoventrally flattened (more so in distal segments), gonocoxites and gonostyli laterally with long, erect, dark bristles (some of them exceeding width of abdomen), the inner side of gonostyli with much shorter setae. Gonocoxites directed dorsolaterad. Gonostyli nearly twice longer than gonocoxites, with acute, claw-shaped inner lobe curved basad. Female abdomen with few, short setae; sternite 8 with oval apical incision; cerci bare, without apical setae. Wings very slightly and evenly infuscated, without markings, except for small darker pterostigma; membrane with conspicuous microtrichia; veins more or less darkened. Body darkened, more so on dorsal side, especially mesonotum; halters with large darkened knob; coxae, proximal part of hind femora, and female cerci pale; setae on body and appendages rather dark.

Variation. In males, 1A often not reaching margin due to its apex atrophied (both wings of holotype and no. 204a). Sometimes im faint or absent (and wing membrane more infuscated: both wings of female no. 204b), or mcu joining M3+4 bifurcation (one wing of female no. 296), or sc-r terminal (another wing of same female).

Measurements (mm). Males larger (wings larger; antennae, fore tarsi and hind legs longer; dimorphism not evident in total body length and length of abdomen, possibly due to male abdomen being more susceptible to shrinkage)—values for males and for females (in parentheses), sexually dimorphic parameters in bold: wing length 1.7–1.95 (1.4–1.53); wing width 0.55–0.67 (0.46–0.53); body length 1.5–1.6 (1.57–1.7); antenna length 1.15 (0.9–1.0); femur 1 length 0.45 (0.45–0.5); tibia 1 length 0.6 (0.55–0.63); tarsus 1 length 0.6 (0.5–0.55); femur 2 length 0.5–0.55 (0.5); tibia 2 length 0.7–0.75 (0.65–0.8); tarsus 2 length 0.5 (0.4–0.5); femur 3 length 0.63–0.65 (0.55–0.6); tibia 3 length 0.9–0.95 (0.75–0.8); tarsus 3 length 0.65–0.75 (0.55–0,63); abdomen length 1.0–1.3 (1.05–1.3); terminalia length 0.2 (0.25).

Etymology. Latin pusillus (tiny), to be treated as adjective.

Figures

FIGURES 1–4. Ewaurista pusilla gen. et sp. nov.: (1–3) holotype male no. 264: (1) habitus, dorsal; (2) wing (vein nomenclature after Wootton & Ennos 1989; Shcherbakov et al. 1995); (3) genitalia, ventral; (4) paratype male no. 204, genitalia, ventral. Scale bars 0.3 mm (1–2), 0.1 mm (3–4).

FIGURES 5–9. Ewaurista pusilla gen. et sp. nov.: (5–7) paratype female no. 332: (5) habitus, lateral; (6) wing; (7) ovipositor, lateral; (8–9) paratype female no. 296: (8) head, anterior; (9) ovipositor, ventral. Scale bars 0.5 mm (5), 0.3 mm (6), 0.1 mm (7– 9).

FIGURES 10–12. Ewaurista pusilla gen. et sp. nov.: 10–11, holotype male no. 264: (10) habitus, dorsal; (11) wing; (12) paratype male no. 517, laterodorsal.

FIGURES 13–15. Ewaurista pusilla gen. et sp. nov.: (13–14) paratype male no. 1038: (13) head, ventral; (14) genitalia, ventral; (15) paratype male no. 436d, genitalia, ventral.

FIGURES 16–21. Ewaurista pusilla gen. et sp. nov.: (16–19) paratype female no. 332: (16) habitus, lateral; (17) wing; (18) head, lateral; (19) ovipositor, lateral; (20–21) paratype female no. 1151d: (20) habitus, lateroventral; (21) ovipositor, lateral.