Caliphaea angka Hämäläinen, 2003

Yang, Guo-Hui, Zhang, Hao-Miao & Orr, Albert G., 2021, Descriptions of larvae of Caliphaea angka Hämäläinen, 2003 and Mnais gregoryi Fraser, 1924 (Odonata: Calopterygidae), Zootaxa 4926 (2), pp. 276-284 : 277

Caliphaea angka Hämäläinen, 2003

( Figs 1 , 2 a–p; 5a–c; 6a)

Material examined. 2³³, 1♀ larvae, 29.V.2020, Sanjiacun Stream (25.51°N, 100.38°E, 2,129 m a.s.l.), Fenyi Town , Dali City, Yunnan Province, China, Guo-Hui Yang leg. Sanjiacun Stream is small montane streams, it is 0.5 m wide, water clear and gravel covered on substrate . 1♀ larva was successfully raised to emergence.

Habitus: A stoutly built caloperygid larva with long legs; coloration overall pale brown heavily mottled with dark brown markings. Lateral gills short and ovate, with robust spines on mid-rib but dorsal and ventral margins smooth ( Figs 1 , 2l ).

Head: Wider than long, about 2.2 times as wide as long and roughly pentangular, Occiput concave, eyes of moderate size, elongate-rounded, situated at sides of head directed mainly forward ( Fig. 1 ). Antenna, 7–segmented, 1 st segment thick, with distinct sub-terminal inward bend, and extremely long, accounting for 2/5 of the whole entire antenna length; terminal segments filiform; length of each antennal segment (mm): 1.65, 0.75, 0.5, 0.45, 0.3, 0.2, 0.1 ( Fig. 2a ). Labium dirty yellow, strongly and abruptly expanded in distal 1/ 2 in dorsal view, distal margin of prementum with small teeth, its apical border strongly produced beyond level of base of palps and very deeply incised, the length of median cleft 2.8 mm, only slightly expanded towards base and rounded at the bottom; width to length ratio of median cleft about 1:5; each lobe bearing a long robust inward directed seta near its inner margin just before the mid-point of the lobe; labial palp with large robust movable hook and three long, curved, sharp end hooks of unequal length at the apex; the inner one being shortest, about 1/4 as long as the long central hook; basal to movable hook palp bears one long and three shorter but robust dorsal setae; outer margin of palp with sparse ‘pelt’ of numerous but much finer setae ( Fig. 2 b–c). Mandibles brown, left mandible with five incisors, L 123450 a(m 1,2, 3,4) 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. 2 e–h). Galeolacinea of maxilla seen in ventral view with six strong curved spines and sparse long setae; maxillary palp narrow, curved and bearing long, dense, fine setae. ( Fig. 2 i–j).

Thorax. Prothorax roughly rectangular, extending slightly laterally, with broad quadrate light marking dorsally. Synthorax brown and smooth, with light brown dorsal triangular mark. Legs long, hind femur reaching the end of S4; all legs with three broad dark brown bands on femora and tibiae. Wing cases parallel and long, forewing cases reaching the anterior margin of S5 and hindwing cases reaching the hind margin of S5 ( Fig. 1 ).

Abdomen. Short, cylindrical, brown and with pale longitudinal irregular-margined dorsal stripes. No lateral spines present. Ovipositor of female extending to basal 4/5 of S10 ( Fig. 2k ). Lateral caudal appendages ovoid, dark brown, with irregular markings on the edges, with 4 big and 5 small robust spines on the mid-rib; middle appendage distinctly smaller, thin and sub-ovate, pale with very broad darker band from near base to post-medially and dark mark at rounded apex ( Fig. 2 m–p).

Measurements (mm). Body length 22; length of the abdomen 12; maximum head width 3, length of the hind femur 6; lateral caudal gill 4.

Differential diagnosis. It is now known that Fraser’s (1943) description of C. confusa is erroneous. Among other, minor differences, it is likely that the forked prementum is less produced in that species than in C. angka but more material needs to be examined before this can be confirmed.

Biological notes. The larva of C. angka was found in small sluggish montane streams, with numerous hydrophytes in the Erhai lake Basin (alt. ca 2,300 –2,800 m) ( Fig. 6a ). Breeding adults ( Fig. 5 a–b) frequent the stream margins. The flight season range from April to August.

During the rearing, we have noticed a rather peculiar behavior. When a larva crawled onto the surface of a stone or on a small branch, its whole body was lifted by stretching of the tibiae, similar to a human doing “push-ups” ( Fig. 5c ). This exercise was performed 15–20 times a day, and may be a territorial display by the larva.

Figures

FIGURE 1. Final stadium larva of Caliphaea angka, dorsal view, one lateral caudal and middle caudal gill missing.

FIGURE 2 (a–p). Caliphaea angka: (a) right antenna; (b) prementum, ventral view; (c) right labial palp, dorsal view; (d) prementum, dorsal view; (e) right mandible, posterior view; (f) same, inner surface; (g) left mandible, posterior view; (h) same, inner surface; (i) left maxilla; (j) right maxilla; (k) female ovipositor, lateral view; (l) caudal gills, dorsal view; (m) lateral caudal gill, lateral view; (n) lateral caudal gill; inner view; (o) lateral caudal gill, dorsal view; (p) middle caudal gill, lateral view.

FIGURE 5 (a–e). Adults and larvae of Calipheae angka and Mnais gregoryi: (a) teneral female of Caliphaea angka freshly emerged in the laboratory; (b) Sexually mature male of C. angka perched on streamside vegetation; (c) larva of C. angka doing push-ups; (d) final instar larva of Mnais gregoryi near emergence in laboratory; (e) mature male of M. gregoryi.

FIGURE 6 (a–b). Habitat of: (a) Caliphaea angka; (b) Mnais gregoryi.