Indonemoura nigrihamita concava Li & Yao, 2017

Li, Weihai, Zhang, Qin, Yang, Ding & Yao, Gang, 2017, A new Chinese species of Indonemoura (Plecoptera: Nemouridae) and a new subspecies of I. nigrihamita Li & Yang, Zootaxa 4311 (2), pp. 255-262 : 259

Indonemoura nigrihamita concava Li & Yao , ssp. nov .

( Figs. 2 , 4 )

Diagnosis. Tergum 9 typical and gradually constricted medially. Epiproct bears rounded but incised apex in dorsal view; ventral sclerite extended apically forward dorsal sclerite forming a short finger-like flagellum. Outer lobe of paraproct forms stout strip around basal margin of cercus at its basal and median portions, with membranous and triangular apical portion.

Adult habitus ( Figs. 4 a, 4b). Males forewing length 6.1–6.2 mm, hindwing length 5.0– 5.1 mm, females forewing length 8.0– 8.2 mm, hindwing length 7.0– 7.2 mm. Head dark brown to black and antennae a little lighter; mouthparts dark brown, compound eyes black. Thorax including pronotum dark brown to black, legs mostly brown, basal portion of femora and tibiae lighter, distal portion of femora darker, hindleg femora with distinct yellow band, band and color pattern on foreleg and midleg less distinct; wings subhyaline with darker veins; Abdominal segments mostly brown except terminalia darker; hairs on abdomen mostly pale brown.

Male Terminalia ( Figs. 2 a–2f). Tergum 9 weakly sclerotized, gradually constricted medially, with two irregular rows of tiny spines but lacking protruding lobes along mid-posterior margin ( Fig. 2 a). Sternum 9 with claviform vesicle, length ca. 4X width, base slightly narrower and dorsolateral aspect sclerotized ( Figs. 2 b, 2c), hypoproct broad and parallel-sided at base, gradually tapering toward tubular tip, covered by dense hairs, overlapping inner lobe of paraproct. Tergum 10 sclerotized, with narrow longitudinal concavity beneath epiproct. Cercus membranous with distinct hairs, length ca. 3X width. Epiproct ( Figs. 2 b–2d) elongate and recurved; basal half nearly parallel-sided, apical half slightly enlarged, apex circular with triangular incision, in dorsal aspect each side with a thin lateral sclerite extended from entire basal sclerite; ventral sclerite sclerotized but medial portion heavier so, broad at base and distinctly narrower toward apex after inserting in dorsal sclerite, extended apically forward dorsal sclerite forming a short finger-like flagellum; in lateral aspect with weakly developed ventral ridge but bearing a row of tiny spines, mostly forward of a median constriction. Paraproct ( Fig. 2 f) divided into 3 lobes: triangular inner lobe sclerotized, mostly hidden by hypoproct; median lobe forming a sclerotized spine-like structure with hook-like apex; outer lobe forming sclerotized strip around basal margin of cercus at its basal and median portions, with membranous and triangular apical portion.

Female ( Figs. 2 g, 4c–4e). Sternum 7 membranous with sclerotized pregenital plate near mid-posterior margin, the plate forming an elevated conical hump followed by a small sclerite until the posterior margin of the segment. Sternum 8 with large sclerotized subgenital plate covering the entire length, the plate generally trapezoidal but with distinct anterior and lateral incisions; the anterior incision deep and bowl-shaped, nearly semicircular and the lateral one shallow and crescent-shaped; the posterolateral corners slightly upraised, connecting to the triangular paragenital plate. Sternum 9 sclerotized with anterior fourth forming a trapezoidal extension, slightly overlapping posterior margin of preceding segment, with a wide shallow mid-anterior incision. Sternum 10 and paraproct typical. Pregenital and subgenital plates covered with dense short setae ( Fig. 4 c).

Type material. Holotype male ( HIST), 1 paratype male ( CAUC), 9 females (5 in HIST, 4 in CAUC), China: Sichuan Province, Aba Zang and Qiang Autonomous Region , Songpan County, Huanglong Scenic Area , Huanglong Temple to Wucai Lake , 3550 m, E 103.83140, N 32.72666, 2011. VIII.2, W.H. Li.

Etymology. The specific name refers to the concave posterior margin of tergum 9 of the male.

Distribution. China (Sichuan Province, Songpan County).

Remarks. The above two males are similar to the holotype male of I. nigrihamita nigrihamita Li & Yang, 2008c from Kangding, western Sichuan Province in most aspects. The two populations are separated> 300 km and we did not collect the new subspecies from nearby Jiuzhaigou County. The major differences are in the shape of tergum 9 and the epiproct apex. The posterior margin of the new subspecies is unmodified and concave but that of I. nigrihamita nigrihamita bears a pair of paramedial protruding lobes at posterior margin; the apex of epiproct has a triangular incision but epiproct apex of I. nigrihamita nigrihamita is entire. Additionally, the median hook of median paraproctal lobe and the apical bulb of the outer paraproctal lobe are directed differently (compare Figs. 2 b, 2f and figs. 37 & 40 in Li & Yang 2008c). the sclerotized lateral margin of the new subspecies ends medially in a swollen apex whereas that of I. n. nigrihamita is forked medially (figs. 37 & 40 in Li & Yang 2008c).

Figures

FIGURE 2. Indonemoura nigrihamita concava Li & Yao, ssp. nov. (a – f male). a. Terminalia, dorsal view. b. Terminalia, ventral view. c. Terminalia, lateral view. d. Epiproct, dorsal view. e. Epiproct, lateral view. f. Paraproct, caudal view. g. Female terminalia, ventral view.

FIGURE 4. Indonemoura nigrihamita concava Li & Yao, ssp. nov. (female). a. Adult habitus, dorsal view. b. Adult habitus, ventral view. c. Female terminalia, ventral view. d. Female terminalia, lateral view. e. Female sterna 7 – 8, ventral view.