Idionyx selysi Fraser, 1926

Zhang, Haomiao & Tong, Xiaoli, 2010, Descriptions of the final instar larvae of three Chinese Idionyx species (Odonata: Anisoptera: Corduliidae), Zootaxa 2716, pp. 53-63 : 56

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

Figures

FIGURES 12 – 15. Larva of Idionyx selysi Fraser: (12) labial mask, dorsal view; (13) left palpal lobe, ventral view; (14) pronotum, dorsal view; (15) antenna.

FIGURES 16 – 20. Idionyx selysi Fraser: (16) head, male, frontal view; (17) thorax and abdomen, male, lateral view; (18) thorax and abdomen, female, lateral view; (19) caudal appendages, male, lateral view; (20) caudal appendages, male, dorsal view.

FIGURES 30 – 35. Inner surface of mandibles of Idionyx larvae: 30 – 31. Idionyx carinata Fraser: (30) right mandible; (31) left mandible; 32 – 33. I. selysi Fraser: (32) right mandible; (33) left mandible; 34 – 35. I. victor Hämäläinen: (34) right mandible; (35) left mandible.

FIGURES 36 – 41. 36 – 37. Idionyx selysi Fraser: (36) final instar larva; (37) male adult; 38 – 39. I. victor Hämäläinen: (38) final instar larva; (39) male adult; 40 – 41. I. carinata Fraser: (40) final instar larva; (41) male adult.