Eugryllacris cf. vaginalis Pictet & Saussure, 1893

Yin, Zi-Xu & Shen, Si-Zhong, 2021, New and little-known Eugryllacris from Yunnan, China (Orthoptera Gryllacrididae: Gryllacridinae), Zootaxa 5026 (4), pp. 541-554 : 545-547

Eugryllacris cf. vaginalis Pictet & Saussure, 1893 (OiÄffi⁂)

Material examined: 1♂ 1♀, China, Yunnan Province, Dehong Dai and Jingpo Autonomous Prefecture , Yingjiang County, Nongzhang Town . (24°34’5”N, 98°1’9”E, Alt. 890), 2-VI-2020, coll. Guichang Liu.

Description. Large species. Fastigium verticis about 2.5-3 times wider than scape; pedicel and first segment of flagellum combined about half length of eyes ( Fig. 3C ; Fig. 4 AB; Fig. 7 BE). Eyes elongate and oval, protruding outwards; ocelli indistinct ( Fig. 4A ). Face smooth; subocular furrows distinct, separate into two branches at their middle part and furrow into clypeo-frontal suture; anterior margin of pronotum projecting in the middle, posterior margin nearly straight; lateral lobes longer than deep, ventral margin straight ( Fig. 4A ).

Tegmen surpass hind knees ( Fig. 7 BE). R releases RS at basal third, both branches forked near tip; MA fused with R in basal area; MP absent; CuA with a single branch that forks at basal third into two veins, CuA1 and CuA2; CuP undivided, free throughout; with five Anal veins ( Fig. 4D ; Fig. 7 BE).

Fore coxa with a spine at fore margin; fore and mid femora unarmed; fore tibiae ventrally with 5 pairs of large spines; mid tibiae ventrally with 5 pairs of spines, dorsally with an internal apical spur; hind femora ventrally with 5-7 external and 4 internal spinules; hind tibiae dorsally with 5-7 external and 5-6 internal spines and a pair of apical spurs, ventrally with 2 preapical spines and an apical spur on both sides.

Male. Ninth abdominal tergite downcurved in apical area, descending in posterior area and split into two hemiglobular regions; two slightly coarse granular oval contact at the splitting midline. Terminal of each split contains a rod-like projection which concave up towards mediad without overlapping. Subgenital plate about twice as wide as long, lateral margin slightly converging. Posterior margin with a medial obtuse-trangularly concave. Styli insert laterally at posterior margin ( Fig. 4E ).

Female. Seventh abdominal sternite of normal size, medial posterior margin nearly straight ( Fig. 4F ). Subgenital plate in basal area rather wide, gradually narrows with a triangular concave at margin and broad obtuse tip ( Fig. 4F ). Ovipositor long and upcurved, reach to hind tarsus when stretched ( Fig. 4G ).

Coloration. General color green when alive; disc of pronotum unicolored. Face overall unicolored, green when alive; base area of mandible light purple when alive, transits into black in inner and tip area; clypeo-frontal suture yellowish pink; tegmen semi-transparent with green veins; hind wing semi-transparent with green or brown veins and veinlets; cells with large dark brown spots; abdomen light green; legs of general color, fore and mid tibia spines yellow with white tips; hind femora spines black; hind tibia spines yellowish green with black tips; all tarsus orangish yellow when alive.

Measurements (mm). Body (from head to tip of abdomen): 31.0–40.9; pronotum: 8.3–9.0; tegmen: 39.0–39.1; fore femur: 12.2–13.2; median femur: 11.1–12.1; hind femur: 19.8–21.1; fore tibia: 13.5–13.7; median tibia: 12.6– 12.8; hind tibia: 20.8–21.3; ovipositor: 31.2.

Natural history. E. cf. vaginalis is univoltine. Hatchlings emerge in around August to October and reach adulthood in around May to July the next year. Female adults were observed to lay eggs into wet napkin rolls in lab ( Fig. 10D ; Fig. 11E ). Eggs undergo a hatching period about two months before hatchlings emerge. Larger nymphs and adults show threat behavior when facing stimulus, with parts of the labrum hides under clypeus showing the jagged mandibles ( Fig. 3D ).

Notes. The pair of rod-like projections and shallow furrow on terminal of male 9 th abdominal tergite, and the shallow concave on hind margin of female 7 th abdominal sternite is unique in the genus except E. tiga sp. nov. from China. However, overall body size of E. cf. vaginalis is much larger than E. tiga , and E. tiga has distinct black dots on legs and pronotum which E. cf. vaginalis does not. The two species is placed to genus Eugryllacris , by the rather wide and short appearance of head and pronotum, and the color pattern of the hind wings which has dark cell centers and light bands along the cross veins. These characters only agree with genera Eugryllacris and Ocellarnaca Gorochov, 2004 , while in other genera hind wings with dark bands run along the cross veins and the cell centers are of light color ( Ingrisch 2018). The shape of male and female abdominal apex of the two species shows their difference with other species of the genus. Far more molecular analyses need to be done to make their relationships more clearly.

Distribution. Nagaland, India; Yunnan, China.

Figures

FIGURE 3. Living Eugryllacris cf. vaginalis female adult. A. lateral view; B. front view; C. dorsal view; D. threat behavior.

FIGURE 4. Features of Eugryllacris cf. vaginalis. A. face; B. dorsal view of pronotum; C. lateral view of pronotum; D. tegmen; E. male abdominal apex; F. female subgenital plate; G. ovipositor. A-D, F, G. female; E. male. A-C. living.

FIGURE 7. Body of Eugryllacris species. A, D. Eugryllacris tiga sp. nov.; B, E. Eugryllacris cf. vaginalis; C. F. Eugryllacris guomashan. A-C. male; D-F. female.

FIGURE 10. Natural history of Eugryllacris. A-C. Eugryllacris tiga sp. nov.; D, E. Eugryllacris cf. vaginalis; F-O. Eugryllacris guomashan. A, H. eclosion; B, D, K. laying eggs; C, E, M. eggs; C, N. hatchling; F, G. coloration comparison of nymphs in same stage at different time; I. Mating couple at the beginning of copulation; J. ending of copulation; L. radial holes on wet phenolic floral foams after laying eggs; O. nymph molts inside its nest.

FIGURE 11. Distribution map of the genus Eugryllacris from Yunnan, China.