Indonemoura furcoloba Li & Yang, 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 : 255-256

Indonemoura furcoloba Li & Yang , sp. nov.

( Figs. 1 , 3 )

Diagnosis. Laterally, the epiproct is nearly parallel but sinuous for most its length with a rounded apex, distinctly tapering apically in lateral view; the median lobe of paraproct is divided into two branches at basal fifth, inner branch longer and stouter with a blunt tip, outer branch slender and spine-like with acute apical tip. The female is characterized by sternum 7 forming a large trapezoid shaped pregenital plate barely covering sternum 8.

Adult habitus ( Figs. 3 a, 3b). Holotype male: Forewing length ca. 4.7 mm, hindwing length ca. 3.9 mm. Female forewing length ca. 6.2 mm, hindwing length ca. 4.9 mm, apex of both wings of one female slightly damaged. General color brown, teneral females yellow brown. Head and antennae dark brown; compound eyes dark; mouthparts brownish. Thorax including pronotum dark brown; pronotum ( Fig. 3 b) nearly quadrate with obtuse corners, lateral margins light brown, medial portion with weak markings; legs uniformly dark brown. Wings subhyaline with dark veins. Abdominal segments brownish but terminalia darker with hairs pale brown.

Male terminalia. Terga 7–8 with sclerotized anterior margins. Tergum 9 ( Fig. 1 a) weakly sclerotized, anterior margin with shallow indentation. Sternum 9 with convex anterior margin except a rounded median notch before a claviform vesicle; vesicle with stalk-like narrow base with slight medial constriction, length> 4X width ( Fig. 1 b); hypoproct broad and subquadrate at basal half, then gradually tapering toward tip, apical fifth tubular and the extreme apex nipple-like. Tergum 10 sclerotized with distinctly sclerotized lateral margins and a pair of bands obliquely across each side of the tergum, a deep median concavity present beneath epiproct, surrounded lateral areas slightly elevated and bearing several spinules along anterolateral margins of the concavity. Cercus membranous with many clothing hairs, generally cylindrical but gently narrowing toward tip, length ca. 2.5X width. Epiproct ( Figs. 1 a, 1c–1d) slender and recurved, with sinuous lateral margins; basal half roughly parallelsided, apical half slightly enlarged with circular apex; in dorsal aspect each side with a thin lateral sclerite, in lateral view, extending along the lowest face; ventral sclerite with darkly sclerotized gourd-like apex, in dorsal aspect, base broad and gradually narrowing, medial portion narrowest until the swollen gourd-like apex. In lateral view, medial portion with weakly developed ventral ridge bearing a row of ca. 10 tiny spines before fusing with dorsal sclerite. Paraproct ( Fig. 1 e) divided into 3 lobes: inner lobe slightly sclerotized, triangular, adhering to median lobe-typical of the genus, nearly as long as outer lobe; median lobe mostly sclerotized, half width of base of paraproct, divided into 2 branches at basal fifth, inner branch mostly parallel-sided, nearly straight but apex slightly out-curved; in ventral view with blunt tip in dorsal view blade-shaped, outer branch slender than inner one, darkly sclerotized and out-curved contacting apex of outer lobe, generally spine-like with sharp tip; outer lobe strongly sclerotized, stripe shaped and adhering to outer margin of the median lobe.

Female ( Figs. 3 c–3e). Sternum 7 mostly membranous, mid-posterior margin greatly produced forming a large trapezoid pregenital plate barely covering sternum 8, as wide as half of width of sternum 7. Sternum 8 moderately sclerotized but subgenital plate not fully sclerotized. Sternum 9 sclerotized with anterior margin slightly extended backward, the mid-anterior portion touching posterior margin of pregenital plate. Sternum 10 and paraproct sclerotized. Pregenital plate with posterior margin in dorsal view nearly truncate with gentle indistinct median notch; in lateral view, slightly downcurved, an inner crescent sclerite underlying the extreme anterior portion of pregenital plate, followed by a pair of medially touching archaic structures together with two triangular brown sclerites beneath anterolateral margins of M-shaped pregenital plate.

Type Material. Holotype: male ( HIST), China: Guangxi Zhuang Autonomous Region, Jinxiu County, Dayaoshan National Nature Reserve , Shengtang Mount., 1170 m, 2008. IV.28, leg. Gang Yao. Paratypes: 2 females ( HIST & CAUC), same data as holotype.

Etymology. The specific name refers to the bifurcate median lobe of paraproct.

Distribution. China (Guangxi Zhuang Autonomous Region).

Remarks. The new species seems to be most similar to I. bilobata Sivec and Stark, 2010 recently described from Thailand in having a comparable epiproct in dorsal view and similar paraprocts, especially the shape of outer lobe in caudal aspect. However, the new species may be separated from I. bilobata by its ventral sclerite of epiproct medially enlarged, and by the median lobe divided at basal fifth with two elongate lobes. In I. bilobata , the ventral sclerite of epiproct lacks the median ridge and bears a small subapical bulging in lateral view (figs. 12 & 14 in Sivec & Stark 2010); the median lobe is bilobed at apex with two short lobes in comparison with I. furcoloba n. sp. (comparing fig. 15 in Sivec & Stark 2010 and Fig. 1 e). The female of I. bilobata is still unknown.

The new species also shares a similar bifurcate median paraproctal lobe with I. trichotoma Li & Yang, 2008b from Yunnan Province, China but it is easily separated from that species by the spineless hypoproctal apex and the stouter outer paraproctal lobe with gently curved apex (comparing figs. 7 & 10 in Li & Yang 2008b and Figs. 1 b, 1e).

Figures

FIGURE 1. Indonemoura furcoloba Li & Yang, sp. nov. (male). a. Terminalia, dorsal view. b. Terminalia, ventral view. c. Epiproct, dorsal view. d. Epiproct, lateral view. e. Right paraproct with part tip of left lobe, caudal view with apex in top view.

FIGURE 3. Indonemoura furcoloba Li & Yang, sp. nov. a. Adult habitus, lateral view. b. Head and pronotum, dorsal view. c. Female terminalia, ventral view. d. Female sterna 7 – 8, lateral view. e. Female sterna 7 – 8, closer ventral view.