Mnais gregoryi Fraser, 1924

(Figs 3; 4 a–m; 5d–f; 6b)

Material examined. 2 ³³ larvae, 25. V.2019, Mt. Jizushan (25.51°N, 100.20°E, 2,340 m a.s.l.), Binchuan Town, Dali City, Yunnan Province, China, Guo-Hui Yang leg.; 4 ³³ larvae, 6 ♀♀ larvae, 4.VII.2019, Yunlong County (25.30°N, 99.02°E, 2,460 m a.s.l.), Dali City, Yunnan Province, China, En-Jiang Zhou leg. Several of these larvae were successfully reared to adults.

Habitus: A fairly lightly built caloperygid lava with relatively short legs; lateral gills long and lanceolate. Body coloration overall dark brown with only obscure darker brown markings in places, without robust spines (Fig. 3).

Head. Roughly pentangular, about 2.2 times as wide as long. Occiput concave. Vertex brown, with small yellow setae (Fig. 3). Antenna, 7-segmented, 1 st segment robust, with slight sub-basal sinuous bend, and extremely long, accounting for 3/5 of the whole entire antenna length; terminal segments filiform; length of each antennal segment (mm): 1.75, 0.25, 0.25, 0.15, 0.10, 0.07, 0.05 (Fig. 4a). Labium pale yellowish, broadly expanded in distal 1/ 2 in dorsal view, distal margin of prementum fringed with very small teeth; extending to form large triangle medially cleft; median cleft nearly touching distally and expanding at base to form a rounded droplet shape, 4.1 mm in length; maximum width to total length ratio of median cleft about 1: 4; labial palp with large movable hook and three long, curved, sharp terminal hooks of unequal length at apex, the inner one curved strongly inward, and shortest, about 1/3 as long as the middle; one strong dorsal setae near base of movable hook (Fig. 4 b–d). Mandibles brown, left mandible with five incisors, L 123450 a(m 1,2, 3)b, 4> 5> 3> 2> 1, molar crest produced straight; R 12345 y a, right mandible with similar incisors, molar crest absent, additional tooth y on the right mandible (Fig. 4 e–h). Galeolacinea of maxilla seen in ventral view with seven strong curved spines and sparse long setae; maxillary palp narrow, curved and bearing long, dense, fine setae. (Fig. 4 i–j).

Thorax. Prothorax brown and roughly rectangular. Synthorax brown and smooth, with a thick dark brown stripe laterally. Legs only moderately long, with two dark brown bandings on femora and two similar bandings on tibiae when alive. Wing cases parallel, forewing cases reaching the hind margin of S3 and hindwing cases reaching the anterior margin of S4.

Abdomen. Brown and smooth with black markings. No lateral spines present. Female ovipositor sheath reaching beyond middle of S10, but never extending beyond its posterior margin (Fig. 4k). Lateral appendages long lanceolate with a prominent main trachea, with smooth lateral margins and a short apical projection; middle appendage about 4/5th length of laterals, with slight point apically. Lateral appendages dark with irregular pale marking around margins; middle appendage dark with two well defined whitish bands (Fig. 4 l–m).

Measurements (mm). Body length 35–37; length of the abdomen 17–18; maximum head width 4, length of the hind femur 8–9; lateral caudal gill 9–10.

Differential diagnosis. Besides M. gregoryi, larvae of three other species the genus have been described, M. andersoni described and illustrated by Matsuki & Lien (1978) from Taiwan in detail, M. pruinosa and M. costalis described by Ishida (1996) and Hayashi et al. (2004) from Japan. The main differences between the species are in the ovipositor sheet of the female, the shape of the lateral gill (narrow or wide) and the shape of the prementum.