Idionyx selysi Fraser, 1926

Figures 12–20, 32–33, 36–37

Material examined. 1 ɗ and its exuviae, 01.IX.2009, Mengla (21°37ʹ0 4ʺN, 101°35ʹ0 3ʺE), Xishuangbanna, Yunnan Province, China, Haomiao Zhang leg.; 1 final stage larva, same data but 03.IX.2009; 1 Ψ and its exuviae, same data, emerged on 30.IX.2009.

Ground color of body yellowish brown with dark brown maculation (Fig. 36). Small sized with total body length 14.0 mm, head width maximum 4.0 mm; length of hind femur 4.5 mm.

Head—Yellowish brown without conspicuous maculation. Eyes large, knob-like; antefrons and hind margin of eyes with short setae; upper surface of frontal plate concave; mandibles similar to I. carinata (Figs 32–33) and with same mandibular formula as in I. carinata, but apices of incisors 1, 3 and 4 pointed; clypeus and labrum entirely concealed beneath broad labial mask (Fig. 12); postmentum extending about halfway between mid and hind coxae; premental setae: 5+4 / 4+5; apex of prementum not bifid, with robust setae, and its distal margin lacking conspicuous crenulations, with 11–13 spiniform setae on each side; palpal lobes strongly developed (Fig. 13), their inner margin with 8 teeth, all with spiniform marginal setae, the outermost one triangle-shaped, others rounded, dark brown; outer margin of lobes with a row of setae; palpal setae: 5 / 5; moveable hook short and pointed at apex. Antennae filiform, 7-segmented (Fig. 15). Length of each antennal segments (mm): 0.16: 0.28: 0.25: 0.17: 0.17: 0.17: 0.25.

Thorax—Thorax almost as broad as the transverse diameter of head. Pronotum strongly developed (Fig. 14) with 3 transverse depressions; synthorax fringed with long setae; wing pads strongly divergent extending to middle of S7. Legs long and slender, femora and tibiae each with 4–5 long, stout, prostrate, clavate setae; front femora yellowish with a dark brown stripe subdistally; middle and hind femora yellowish with two dark brown stripes submedially; tibiae yellowish with a dark brown marking basely.

Abdomen—Short and oval, depressed, ground color yellowish brown, all segments fringed laterally with long hair-like setae; S4 & 10 with a pair of small dark brown spots dorsally, S5–9 with two pairs of dark brown spots dorsally, S5–8 with a pair of central brown spots ventrally; dorsal hooks absent; large lateral spines present only on S8 & 9; S10 short; anal appendages short, epiproct and paraprocts straight, triangular, cerci subequal to paraprocts in length.

Distribution. China (Yunnan), Laos, Burma, and Thailand