Amphinemura yadonga Li, Yang and Li, 2024

Li, Meng-Yu, Yang, Ding & Li, Wei-Hai, 2024, Two new species of Amphinemura (Plecoptera: Nemouridae) from south-western China, Journal of Natural History 58 (17 - 20), pp. 645-655 : 649-653

Amphinemura yadonga Li, Yang and Li , sp. n.

Type material

Holotype. 1♂, China, Xizang Autonomous Region , Yadong County, 3400 m, 27.538°N, 88.990°E, 12 July 2018, leg. Zhu Ya-Jun ( CAU).

Paratypes. 2♂♂, 2 ♀♀, same data as the holotype .

Description

Adult habitus. Body colour brown to dark brown. Head, compound eyes black; mouthparts brown, and palpi yellow; antennae brown. Thorax brown to dark brown; pronotum dark brown but anterolateral portion brownish; legs light brown, tarsi darker. Wing membranes subhyaline with brown veins. Abdomen brown with darker terminalia.

Male. ( Figures 3a–d , 4 , 5g –l ). Forewing length 5.3–6.3 mm, hindwing length 4.7–5.3 mm. Tergum IX ( Figures 3a , 4a ) sclerotised except medial portion distinctly sclerotised, rather constricted medially, with a row of long hairs along posterior margin. Vesicle of sternum IX ( Figure 3b ) claviform, slightly constricted basally, weakly swollen medially, apex slender. Hypoproct ( Figure 3b ) slightly sclerotised, basally wide and square, medially gradually tapering to nipple-like apex but with a subapical bulge. Tergum X ( Figures 3a , 4a ) sclerotised, a large medial membranous concavity present beneath epiproct, covered by scattered spinules along lateral margins of concavity. Cercus ( Figure 3a, b ) slightly sclerotised, nearly cylindrical, with dense hairs, much longer than wide. Epiproct ( Figures 3a, c , 4 a, c, d , 5g –i ) long and recurved; medial portion slightly enlarged and basally portion sclerotised. Dorsal sclerite with a pair of strongly sclerotised filaments originating from wide basal brown band. Ventral sclerite with a triangular, sharp ridge fringed with several spines. Paraproct ( Figures 3b, d , 5j ) trilobed: inner lobe rectangular, moderately long, apex bilobed; median lobe claviform, distally strongly upcurved, with a subapical membranous area and 8–10 long black spines; outer lobe forming an s-shaped sclerite, much shorter than median lobe, apex with 2–3 shorter black spines.

Female. ( Figures 3e–f , 5k–l ). Forewing length 6.5–7.0 mm, hindwing length 5.5–6.0 mm. Sternum VII ( Figures 3e , 5k ) posteriorly produced into a large sclerotised oval pregenital plate, covering anterior half of sternum VIII. Subgenital plate of sternum VIII ( Figures 3e , 5k ) with a pair of thin, sclerotised, transverse bars, separated by a narrow triangular notch. Paragenital plate paired, forming small brown lobes near posterolateral corner of subgenital plate. Sternum IX ( Figures 3e , 5k ) sclerotised, anteromedially triangularly produced. Paraprocts wide triangular, with blunt tip; cerci short and brownish.

Inner genitalia ( Figures 3f , 5l ) in dorsal view, originating from under the subgenital plate, opening narrow and triangular; anterior shield sub-equally trilobed, lateral lobes each fused with a slender triangular anterolateral sclerites, the lobe also contacting a drop-shaped posterolateral sclerite and larger membranous triangular lobe beside the medial pouch; the pouch is from the medial lobe of anterior shield and ending in a tubular sclerite extended to the receptacle and primary genital organs; a pair of round mesolateral sclerites located between posterolateral sclerites and anterolateral corners of subgenital plate.

Nymph

Unknown.

Etymology

The specific name refers to the type locality, Yadong County.

Remarks

The new species is similar to A. dentata Zwick, 1977 , a species described from Bhutan. The two species share a dorsal surface of epiproct and outer lobe of paraproct. However, A. yadonga can be easily separated from A. dentata by the bilobed inner paraproct lobe, and the trifid apex of outer lobe of paraproct. In A. dentata , both the outer lobe of paraproct and inner paraproct lobe are entire (figs. 13–14 in Zwick 1977). Additionally, their ventral sclerites are superficially similar but differ in detail: in A. yadonga , the ventral sclerite of the epiproct forms a spinose ridge while in the Bhutanese species, A. dentata , the ventral sclerite has a single, large fang (fig. 16 in Zwick 1977).

The female of A. yadonga Li, Yang and Li , sp. n. can be easily distinguished from females of the hitherto known Oriental Amphinemura species on the basis of the distinctive shape of the subgenital plate.

Figures

Figure 3. Amphinemura yadonga Li, Yang and Li, sp. n. (a–c) male terminalia (dorsal view; ventral view; lateral view); (d) right paraproct, posterior view; (e) female terminalia, ventral view; (f) cleared female genital sclerites, dorsal view.

Figure 4. Amphinemura yadonga Li, Yang and Li, sp. n. (a) male terminalia, dorsal view; (b) right paraproct, dorsal view; (c) epiproct, dorsal view; (d) epiproct apex, dorsal view.

Figure 5. Amphinemura bicolorata Li, Yang and Li, sp. n. (a–f) and Amphinemura yadonga Li, Yang and Li, sp. n. (g–l). (a, g) male epiproct, dorsal view; (b, h) cleared male epiproct, dorsal view; (c, i) male terminalia, lateral view; (d, j) male right paraproct,posterior view;(e, k) female terminalia, ventral view; (f, l) cleared female genital sclerites, dorsal view.