Amphinemura bicornata, Mo & Wang & Yang & Li, 2020

Mo, Raorao, Wang, Guoquan, Yang, Ding & Li, Weihai, 2020, Two new species of Amphinemura (Plecoptera: Nemouridae) from Damingshan National Natural Reserve of Guangxi, China, Zootaxa 4751 (1), pp. 131-142 : 137-139

Amphinemura bicornata sp. nov.

( Figs. 5–7 )

Male habitus ( Fig. 5a ). Body color generally dark brown. Head, mouthparts and pronotum dark brown; antennae and palpi brown; compound eyes black; head wider than pronotum; pronotum rectangular, corners rounded, with indistinct markings; legs brown. Wing membranes subhyaline, veins blackish brown. Abdominal segments brown with darker terminalia.

Male ( Figs. 5–7 ). Forewing length ca. 6.6 mm, hindwing length ca. 5.4 mm. Tergum VIII sclerotized, except median area and posterior margin poorly sclerotized. Tergum IX distinctly sclerotized, slightly concaved at anterior margin, with a small triangular emargination posteromedially and with two paramedial groups of black spinules and long hairs present along mid-posterior margin ( Figs. 5b, 5d , 6a ). Slender vesicle of sternum IX claviform, length 3.7 X maximum width, constrict basally and subapically, with a slightly swollen tip ( Figs. 5 c–5d, 6b). Hypoproct triangular with a nipple-like tip; ventral surface covered with many long hairs. Tergum X darkly sclerotized, a membranous concavity present below the epiproct ( Figs. 5b, 5d , 6a ). Cercus short, sclerotized and weakly curved inward. Epiproct ( Figs. 5b, 5d , 6a, 6 c–6f) rectangular, basally wide and rounded, with a pair of double black outcurved lateral processes and a thin median process. Dorsal sclerite mostly membranous, broad suboval basal half; lateral arms strongly sclerotized and basal portion hidden beneath the large membrane, subapically outcurved and downcurved, appearing as a pair of black horn-like processes with several denticles either side of tip, but lateral aspects of hornlike processes weakly sclerotized. Ventral sclerite strongly sclerotized, triangular, broad at base, tapering toward tip that is inserted into dorsal sclerite between folds of dorsal sclerite, strongly up-curved but curved downward apically in lateral view, expanded ventrally into a large subrectangular ridge with a group of small black spines and several scattered larger black spines. Paraproct trilobed ( Figs. 5 b–5d, 6a–6b, 7): inner lobe sclerotized and subtriangular with a rounded tip; median lobe distinctly sclerotized, S-shaped, basally outcurved, curved inward medially but outcurved again subapically, forming a rounded, membranous apex with several black long spines along outer edge; outer lobe slender and heavily sclerotized, distinctly curved outward apically.

Female. Unknown.

Type Material. Holotype male ( HIST), CHINA: Guangxi Zhuang Autonomous Region, Nanning City , Wuming County, Damingshan National Natural Reserve , 300 m, N 23°30’, E 108°26’, 2011.VIII.14, H. Dong.

Etymology. The name refers to a pair of horn-like processes in epiproct. Latin “bi-” means two, and “cornu” means horn.

Distribution. China (Guangxi Zhuang Autonomous Region).

Remarks. Amphinemura bicornata is a member of the A. sinensis species group as proposed by Li et al. (2018), with males possessing a pair of lateral processes and a median process of the epiproct. The male of the new species is most similar to A. fleurdelia ( Wu, 1949) described from Fujian Province of the southeastern coast of China and Guangdong Province also of southeastern China, bordering Hong Kong, in having a pair of large outcurved and downward horn-like lateral projections, the broaden basal ½ of epiproct, a shorter median process with a downward apex in lateral view, the triangular inner lobe of paraproct and rounded, membranous apex of median lobe with long spines, and outcurved outer lobe of paraproct. The male of A. bicornata may be separated from A. fleurdelia by the thicker and shorter lateral projections at about ⅔ of epiproct with several apical denticles, the ventral scler- ite nearly rectangular in lateral view fringed with a group of small black spines and several scattered larger black spines, spines of median lobe of paraproct thicker and apical ½ of outer lobe of paraproct naked. In A. fleurdelia , lateral projections of epiproct are about ¾ of epiproct without apical denticles, the ventral sclerite is flat with rows of spines, the spines of median lobe of paraproct are thin, and apical ½ of outer lobe of the paraproct with several spines.

Figures

FIGURE 5. Amphinemura bicornata sp. nov. (male). a. Head and pronotum, dorsal view. b. Terminalia, dorsal view. c. Terminalia, ventral view. d. Terminalia, lateral view.

FIGURE 6. Amphinemura bicornata sp. nov. (male). a. Terminalia, dorsal view. b. Terminalia, ventral view. c. Epiproct, dorsal view. d. Epiproct, dorsal view. e. Epiproct, lateral view. f. Epiproct, lateral view.

FIGURE 7. Amphinemura bicornata sp. nov. (male). a. Left paraproct, ventral view. b. Tip of outer lobe of left paraproct, dorsal view. c. Left paraproct, ventral view. d. Tip of median lobe of left paraproct, caudal view.