Amphinemura dabanshana Li, Du & Yang

Li, Weihai, Du, Kaishu & Yang, Ding, 2017, Two new species of the nemourid genus Amphinemura (Plecoptera: Nemouridae) from China, Zootaxa 4254 (4), pp. 485-492 : 485-487

Amphinemura dabanshana Li, Du & Yang , sp. nov.

Figures 1 & 3 .

Diagnosis. The males of this new species are characterized by the dorsal sclerite of epiproct with two slender, darkly sclerotized lateral bands with an apicolateral ear-shaped membrane in dorsal view ( Fig. 1 c); the ventral sclerite is expanded with a triangular ventral ridge with a row of spines mostly hidden by the dorsoapical lateral membrane ( Fig. 1 g). The paraproctal median lobe has a pod-shaped apex with a row of five large parallel subapical spines in dorsal view, the spines being much longer than width of the apex ( Fig. 1 a).

Adult habitus ( Figs. 3 a, 3b). Head mostly brown to dark brown, an L-shaped dark marking reaching each ocellus and base of antenna, occiput darker; antennae brown, scape and pedicel darker. Thorax brown, pronotum trapezoidal with scattered rugosities, anterior corners rounded; legs brown. Wing membranes subhyaline with brown veins. Abdomen brown with darker terminalia.

Male ( Fig. 1 ): Forewing length 4.0– 4.1 mm, hind wing length 3.3–3.4 mm. Terga I–VIII each with medially interrupted sclerotized anterior margin. Tergum IX weakly sclerotized except median portion darkly sclerotized, with rounded meso-anterior indentation; several tiny spines present along median portion of posterior margin ( Fig. 1 a). Vesicle of sternum IX claviform, slightly constrict basally and gradually swollen toward rounded tip ( Fig. 1 b). Hypoproct subquadrate at basal half, then gradually narrowing toward upcurved, nipple-like tip ( Fig. 1 b). Tergum X sclerotized, an usual medial concavity present beneath epiproct, covered by several rows of spinules along anterolateral margins of the concavity. Cercus membranous covered with dense hairs, much longer than wide. Epiproct ( Figs. 1 a, 1c–1f) long and recurved; generally rectangular, about 2X longer than wide, medial portion slightly enlarged and apical portion swollen with membranous lateral ears which is distinct after treatment of KOH in dorsal view, in half-posterior view, the apex is slightly tapering and the lateral band slightly convergent subapically before KOH treatement ( Figs. 1 e, 1f). Dorsal sclerite with two slender, darkly sclerotized lateral bands, the band slightly enlarged basally, in lateral view the upper portion mostly membranous but with obscure brown band nearly parallel to lateral bands. Ventral sclerite with a triangular, sclerotized ridge fringed with a row of tiny spines subapically, mostly hidden by the dorsoapical lateral membrane ( Fig. 1 g). Paraproct divided into three lobes: outer lobe forming an S-shaped curved, parallel-sided sclerite, apex pod-like and upcurved, with ca. 8–10 slender spines, the apex partly hidden by much larger apex of median lobe; median lobe basally fused with outer lobe, basal half wide, constrict medially, then up-curved in a pod-shaped apex with a row of 5 grand subapical dorsal spines and 1–2 smaller ventrolateral spines, the large spines being much longer than width of the apex; inner lobe sclerotized and band like, base partly hidden by hypoproct, apex moderately wide and truncate, nearly as long as outer lobe ( Fig. 1 b).Female. Unknown.

Type material. Holotype male ( HIST), CHINA: Qinghai Province, Qinghai, Datong County, Qilian Mountain Range, Baoku Nature Reserve , Daban Mountain , Chahan River , 2,880–3,100 m a.s.l., N 37°16.20' E 101°30.28', 15.VIII.2015, leg. Weihai Li . Paratypes: 1 male (HIST), 1 male ( CAU), same data as holotype.

Etymology. The species is named after the type locality, Daban Mountain also known by the Chinese name Dabanshan.

Distribution. The new species was collected from the Chahan River in the Baoku Nature Reserve, in northern Datong County, Qinghai Province of the Qinghai-Tibetan Plateau. The Chahan River is a first order tributary of Baoku River. At the collection site, the stream is fast flowing with rubble and cobble substrate and with extensive riparian vegetation. Adults of the new species were found on stones near the rapid main channel of the stream ( Fig. 3 c).

Remarks. Regarding the pod-like structure of the paraprocts, the new species appears similar to A. ctenospina Li & Yang, 2008b from Yunnan Province of southwestern China. However, the smaller pod-shaped paraproctal outer lobe and distinct spinulation of the apical row of grand spines of the median paraproctal lobe readily distinguish it from that species.

Figures

FIGURE 1. Amphinemura dabanshana sp. nov. (male). a. Terminalia, dorsal view with right paraproct enlarged in oblique view. b. Terminalia, ventral view. c – d. Epiproct, dorsal view. e – f. Epiproct and its apical half, respectively, dorsal, half posterior view, showing variation before KOH treatment. g. Epiproct, lateral view.

FIGURE 3. Amphinemura dabanshana sp. nov. a. Habitus, dorsolateral view. b. Head and pronotum, dorsal view. c. Type locality, Chahan River.