Afronurus gilliesiana (Braasch, 1990)

Figs 5A-E, 6A-E, 7A-C, 8A-E, 17C, D

Cinygmina gilliesiana Braasch, 1990: 8, figs 13-16, original description (nymph).

Afronurus gilliesiana - Boonsoong and Braasch 2013: 86.

Material examined.

5 nymphs, Chiang Rai Prov., Khun Korn waterfall, 19°51'46.10"N, 99°39'4.70"E, 534 m, 6.V.2019, W. Anuntaya leg. (ZMKU); 4 nymphs, Chiang Rai Prov., Nang Lae Nai Waterfall, 20°3'9.50"N, 99°49'16.90"E, 529 m, 6.V.2019, W. Anuntaya leg. (ZMKU); 3 larvae Chiang Rai Prov., Pong Phrabat Waterfall, 20°0'41.80"N, 99°48'15.10"E, 470 m, 7.V.2019, W. Anuntaya leg. (ZMKU) .

Description.

Nymph. See Braasch (1990: 8, 10, figs 13.1-13.4, 14-16, original description).

Adult. Male subimago (in alcohol, Fig. 7A, C, E). Head. Eyes rounded, blackish on both dorsal and ventral parts, pale laterally. Thorax. Yellowish with triangular brown patch on sub-median of mesonotum. Forelegs brownish; lengths of femur, tibia, and tarsi 1.64 mm, 1.24 mm, and 0.63 mm, respectively. Midlegs brownish; lengths of femur, tibia, and tarsi 1.68 mm, 1.38 mm, and 0.72 mm, respectively. Hindlegs brownish; lengths of femur, tibia, and tarsi 1.7 mm, 1.42 mm, and 1.22 mm, respectively. Wings transparent; forewing C, Sc and RA thick and yellowish brown, other veins thinner, Sc and RA parallel along the wing, convergent at base, RS and MP forked basally, MA forked at the middle, and CuP and CuA adjacent at base; hindwings rounded, RA and MA adjacent at base of wing, MA and MP forked at the middle (Fig. 7E). Abdomen. Middle area brown with one pair of longitudinal yellow marks, outer margin pale yellow (Fig. 7A). Genitalia: penis bilobate, expanding laterally to the enlarged lobes, the inner part of lobes with a small cleft (Fig. 17C). Titillators very short, canine-like (Fig. 17C, D), forceps 4-segmented, segment I very small, length ratio of segment II to segment III to segment IV is 0.29: 0.12: 0.1 (Fig. 7C).

Female subimago (in alcohol, Figs 7B, D). Head. Eyes rounded with brownish dorsal part and ventral part dark brown. Thorax. Yellowish with brown patch at margin. Midlegs brownish; lengths of femur, tibia, and tarsi 1.89 mm, 1.46 mm, and 0.66 mm, respectively. Hindlegs brownish; lengths of femur, tibia, and tarsi 2.3 mm, 1.49 mm, and 0.57 mm, respectively. Wings as in male imagos. Abdomen. Tergites VII-IX, middle area pale brown with one pair of pale marks on anterior margin, tergite X pale yellow (Fig. 7B). Subanal plate trapezium-shaped and concave at tip (Fig. 7D), length 0.2 mm, width 0.5 mm.

Egg.

Chorionic surface covered with pKCTs and eKCTs. Both poles densely covered with pKCTs. Equatorial and subequatorial areas with eKCTs and micropyle beside eKCTs (Fig. 8C); area between pKCTs and eKCTs with indistinct small tubercles (Fig. 8B), areas of two poles of pKTCs ~ 0.7 × the size of the whole egg (Fig. 8A).

Remarks.

Nymph of Afronurus gilliesiana is distinguishable from other species by gill shape, particularly oval-elongated gill I as well as by two large round femoral markings (Figs 5E, 6D). Anterior margin of head with four weak markings (Fig. 5D). Abdomen with marking as shown in Fig. 5A, tergites VIII and IX with pale markings (Fig. 5B) and sternites without marks (Fig. 5C). Gill V (Fig. 6A) and gill VI (Fig. 6B) obliquely rounded, triangular, with small projection; gill VII (Fig. 6C) broad and asymmetrically oval. Bristles on dorsal face of hind femur spatulate in shape (Fig. E).

Adult male can be distinguished by its genitalia: penis bilobate, expanding into laterally enlarged lobes, the inner part of lobes with a small cleft (Fig. 17C).

Habitat.

The nymph of Afronurus gilliesiana was reported by Braasch (1990) from Mae Sot district, Tak province in northern Thailand. In this study, A. gilliesiana was found restricted to three localities in Chiang Rai province. The habitats are unique with high mountain areas, waterfalls, base rock, and some areas of cobbles. The altitude is higher than 400 meters. The nymphs were found attached to the cobbles, away from the base rock with strong water falling from the waterfall. The male and female adults and eggs are described for the first time.

Distribution.

Chiang Rai province (Fig. 18).