Amphinemura hainana, Li, Weihai & Yang, Ding, 2008

Li, Weihai & Yang, Ding, 2008, A new species of Amphinemura (Plecoptera: Nemouridae) from China, Zootaxa 1892, pp. 65-68 : 65-68

Amphinemura hainana sp. nov.

( Figs. 1 – 11)

Diagnosis. Males of this species are characterized by a pair of large, falcate, dorsomedially curved projections on the tenth tergum. In both sexes, the terminal costal crossveins of the forewing are usually reduced or absent and the stigma is usually darkened. Female subgenital plate lobes are thickened on their anterolateral surfaces and the lobes cover the median notch of the subgenital plate.

Male. Small, body length 2.7–3.2 mm, forewing length 3.4–3.8 mm, hindwing length 2.8–3.2 mm. Head ( Figs. 2 a & b) brown, ocellar triangle more darkly pigmented, usually radiating into a cross-shaped marking, sometimes head evenly dark in older specimens. Head slightly wider than pronotum; compound eyes dark; antennae yellowish brown at basal 1/ 3 and gradually forming dark distal flagellum; mouthparts brownish except labrum dark brown. Thorax dark; pronotum ( Fig. 3 ) pale brown, subquadrate angles bluntly rounded, shallow curved groove along anterior margin and two groups of lightly colored rugosities scattered in irregular patches on each side of midline; 2 highly branched cervical gills of nearly equal length present, 1 on each side of lateral cervical sclerite, inner gills forming 5 branches and outer gills 7 branches. Legs uniformly brown. Wings ( Figs. 1 a & b) subhyaline with discontinuous brown pigmentation along costal margin, terminal costal crossveins usually reduced or absent, where absent the proximal margin of the dark stigma aids in discrimination of the typical nemourid “X” pattern. Abdomen brown with hairs mostly pale.

Terminalia (Figs. 5-11): Tergum 9 weakly sclerotized except anterior margin which is heavily sclerotized, a medial sclerotized area bears several tiny black spines and hairs posteriorly. Sternum 9 with a shallow anterior emargination, vesicle slender, slightly enlarged medially; hypoproct basally broad and nearly rectangular, gradually tapering toward tubular tip. Tergum 10 mostly sclerotized but with large, longitudinal membranous area along midline under epiproct with two groups of tiny spines at anterolateral margins; a pair of large, falcate, dorsolateral projections curved dorsomedially. Cercus sclerotized, with narrow basal bar, much longer than wide. Epiproct rectangular with a round tip; dorsal sclerite broad at base and expanding dorsolaterally, with darkly sclerotized lateral margins incurved apically; ventral sclerite sclerotized, broad at base and narrowing toward tip, sometimes slightly extending beyond tip of dorsal sclerite, expanded ventrally into semicircular ridge with two rows of black spines in lateral view. Paraproct encompassed basally by a sclerotized bar, three-lobed: outer lobe distinctly sclerotized, with broad base, fused with median lobe apically to form conjoined tip with two or three spines; median lobe sclerotized and dorsomedially curved, a distinct subapical spine present; inner lobe slightly sclerotized but with dark apex and bifurcate tip, half the length of median lobe.

Female. Body length 3.5–4.0 mm, forewing length 4.1–4.2 mm, hindwing length 3.3–3.5 mm. General color pattern and wing characters resemble those of males.

Sternum 7 with a pentagonal, sclerotized pregenital plate reaching anterior margin of sternum 8. Subgenital plate lobes with anteromedial portion thickened. Sternum 8 with four transverse sclerotized bands along posterior margin, the median two small, subquadrate and the lateral two strip-like. Cerci membranous, cylindrical, longer than wide.

FIGURES 5–11. Amphinemura hainana sp. nov. (male). 5. Terminalia, dorsal. 6. Terminalia, ventral. 7. Terminalia, lateral. 8. Epiproct, dorsal. 9. Epiproct, lateral. 10. Right paraproct, caudal. 11. Cercus, dorsolateral.

Nymph. Unknown.

Ecological notes. The species seems restricted to cool water streams. Adults were collected from vegetation or mineral substrates at or near the water’s edge. Many other stoneflies were present in the same habitat including Leuctra , Neoperla and Acroneuria . Other Nemouridae were rarely found to coexist with the new species.

Type material. Holotype male, CHINA: Hainan, Ledong, Jianfengling, Nantianchi, 18o75'N, 109o17'E, 810 m, 2007. V.5-7, Jingxian Liu. Paratypes: 3 females, same data as holotype; 10 males and 21 females, Hainan, Lingshui, Diaoluo Mountain, 18o48'N, 110o02'E, 940 m, 2007. X.27, Ding Yang; 4 males and 3 females, Hainan, Baisha, Yuanmen, Hongmao village, 19o23'N, 109o44'E, 430 m, 2007. X.19, Ding Yang; 2 males and 4 females, Hainan, Changjiang, Bawangling, Dong’er Station, 19o25'N, 109o03'E, 1000 m, 2007. X.22, Ding Yang; 29 males and 16 females, Hainan, Wuzhi Mountain, Shuiman, Guanshantai, 18o76'N, 109o51'E, 600 m, 2007. X.29, Ding Yang; 2 males and 5 females, Hainan, Baisha, Yuanmen, Hongmao village, 19o23'N, 109o44'E, 430 m, 2007. X.18, Ding Yang; 7 males and 8 females, Hainan, Ledong, Jianfengling, 18o75'N, 109o17'E, 800 m, 2007. X.24, Ding Yang; 2 males and 1 female, Hainan, Changjiang, Bawangling, Dong’er Station, 19o25'N, 109o03'E, 1000 m, 2007. X.21, Ding Yang; 1 male, Guangxi, Fangcheng, Shiwandashan, 2006. VIII.28, 21 o77'N, 108o35'E, 1400 m, Xingyue Liu; 1 male and 2 females, Hainan, Changjiang, Bawangling National Nature Reserve, 19o25'N, 109o03'E, 1000 m, 2007. V.24, Kuiyan Zhang; 1 male, Yunnan, Hushui, Chenggan, 28o84'N, 98o85'E, 900 m, 2007. V.11, Xingyue Liu; 2 males, Hainan, Shuiman, Wuzhi Mountain, 18o76'N, 109o51'E, 2007. V.16, Kuiyan Zhang; 3 males and 10 females, Hainan, Wuzhi Mountain, Shuiman, Guanshantai, 18o76'N, 109o51'E, 600 m, 2007. V.16, Junhua Zhang; 1 male, Inner Mongolia, Dongsheng, 39o82'N, 109o96'E, 2006. VIII.27, Maoling Sheng; 7 males and 9 females, Hainan, Shuiman, Wuzhi Mountain, 18o76'N, 109o51'E, 600 m, 2007. V.26, Jingxian Liu; 1 male and 1 female, Hainan, Baisha, Yuanmen, Hongmao village, 19o23'N, 109o44'E, 430 m, 2007. V.22, Junhua Zhang; 1 male, Hainan, Ledong, Jianfengling Station, 13th section, 18o75'N, 109o17'E, 2007. V.11, Junhua Zhang, 2 males and 2 females, Hainan, Baisha, Yuanmen, Hongmao village, 19o23'N, 109o44'E, 430 m, 2007. V.22, Kuiyan Zhang; 2 males and 1 female, Hainan, Shuiman, Wuzhi Mountain, 18o76'N, 109o51'E, 600 m, 2007. V.17, Kuiyan Zhang; 2 males and 9 females, Hainan, Lingshui, Diaoluo Mountain, 18o48'N, 110o02'E, 940 m, 2007. V.30, Jingxian Liu; 2 males and 3 females, Hainan, Shuiman, Wuzhi Mountain, 18o76'N, 109o51'E, 600 m, 2007. V.18, Jingxian Liu.

Distribution. The new species is known only from China (Guangxi, Hainan, Inner Mongolia, Yunnan).

Etymology. The specific epithet refers to the type locality, Hainan, the province that harbors the insect in abundance.

Remarks. This is an odd species of the genus Amphinemura in that it has prong-like extensions on tergum 10 and slight modifications of the cerci that differ from other members of Amphinemura . However, the major parts of the genitalia, the epiproct and the paraprocts are typical of the genus Amphinemura . The slight modifications of the cerci are minor and the wing vein variability falls easily within the genus Amphinemura . The slight differences in the female subgenital plate are also typical of many Amphinemura species ( Aubert 1967). The modifications on these ancillary characters may contribute to the successful status of the genus.

Acknowledgments. We are very indebted to Mr. Jingxian Liu, Dr. Xingyue Liu and Prof. Maoling Sheng for their assistance in collecting specimens. We also heartily thank Dr. Yajun Zhu, Ms. Kuiyan Zhang and Dr. Junhua Zhang for preparing and providing the specimens. We also thank Dr. Richard W. Baumann for critical review of this manuscript. The research was supported by the National Natural Science Foundation of China (No. 30225009) and the Ministry of Science and Technology of the People's Republic of China (MOST grant No. 2006FY 110500).

Figures

FIGURES 1 – 4. Amphinemura hainana sp. nov. (male). 1. Wing, a. common; b. rare. 2. Head showing color pattern, a. common; b rare. 3. Pronotum, dorsal view. 4. Female terminalia.