Nazeris biacuminatus Hu & Qiao, 2019

Hu, Jia-Yao & Qiao, Yu-Jia, 2019, Five new species of Nazeris Fauvel in Guangxi, China (Coleoptera, Staphylinidae, Paederinae), Zootaxa 4543 (3), pp. 431-441 : 438-439

Nazeris biacuminatus Hu & Qiao , sp. n.

(Figs 5, 30–34)

Type material. Holotype: CHINA: male, ‘ China : Guangxi Prov., Xing'an County, Mao'ershan N. R., 450–650 m, 25.VII.2012, Hu & Song leg.’ (SNUC). Paratypes: 1 female, same data as holotype .

Description. Body length 6.2–7.3 mm; forebody length 3.6–3.7 mm.

Body (Fig. 5) dark brown; antennae and legs yellowish brown.

Head ( Fig. 30 ) 1.03–1.05 times as long as wide; punctation very dense, moderately coarse, distinctly umbilicate and not confluent, interstices lacking microsculpture; postocular portion approximately 1.7 times as long as eye length.

Pronotum ( Fig. 30 ) 1.17–1.20 times as long as wide, approximately as long and 0.87–0.88 times as broad as head; punctation non-umbilicate, moderately dense and as coarse as that of head; midline posteriorly with very short and narrow impunctate elevation; interstices lacking microsculpture.

Elytra ( Fig. 30 ) 0.63–0.66 times as long as wide, 0.53–0.54 times as long and as broad as pronotum; punctation as dense and coarse as that of pronotum; interstices lacking microsculpture.

Abdomen with punctation dense and rather coarse on tergites III–IV, dense and less coarse on tergite V–VI, moderately dense and fine on tergites VII–VIII; interstices lacking microsculpture.

Male. Sternite VII ( Fig. 31 ) with posterior margin nearly truncate in the middle. Sternite VIII ( Fig. 32 ) with triangular posterior excision. Aedeagus ( Figs 33, 34 ) weakly sclerotized; ventral process long, with pair of small laminae in basal third, apex divided into two straight branches in ventral view; dorso-lateral apophyses very slender and nearly straight, not reaching apex of ventral process.

Distribution and habitat data. The species is known only from Mao'ershan in northeast Guangxi. The specimen was collected by sifting leaf litter at altitudes of 450– 650 m.

Comparative notes. This species is most similar to N. exilis Hu & Li (Hu & Li 2017: 338, Figs 20–24 ) in general appearance and aedeagal characters, but can be separated by the truncate posterior margin of male sternite VII ( Fig. 31 ), by the wider apical branches of ventral process of the aedeagus ( Fig. 33 ), and by the straight and more slender dorso-lateral apophyses of aedeagus ( Fig. 34 ).

Etymology. The specific epithet (Latin, adjective: acuminate) alludes to the apically divided ventral process of aedeagus in ventral view.

Figures

FIGURES 30–34. Nazeris biacuminatus 30. forebody; 31. male sternite VII; 32. male sternite VIII; 33. aedeagus, in ventral view; 34. aedeagus, in lateral view. Scale bars: 30: 1 mm, 31–34: 0.5 mm

FIGURES 17–24. Nazeris rugosus 17. forebody; 18. dorsal surface of head; 19. ventral surface of head; 20. abdominal tergite VI; 21. male sternite VII; 22. male sternite VIII; 23. aedeagus, in ventral view; 24. aedeagus, in lateral view. Scale bars: 17: 1 mm, 18–20: 0.1 mm, 21–24: 0.5 mm