Nazeris serratimarginatus Yang & Hu 2025, sp. nov.

Nazeris serratimarginatus Yang & Hu sp. nov. Figs 1D, 5A–G Type material. Holotype: CHINA: male:“China: Yunnan, Zhaotong, Wumengshan N.R., Xiaocaoba, 27°50’15.3’’N, 104°17’31.6’’E, 1709 m, 20.vii.2023, Wei Guohao leg. [云南省DZdz市乌ae山保护区小¤坝ṆḄ区]” (SNUC). Diagnosis. Body reddish brown; head with umbilicate punctation; abdominal tergites lacking microsculpture; aedeagal ventral with drop-shaped cavity in the middle; dorso-lateral apophyses with small and dense sawteeth at basal half of lateral margin in ventral view, extending slightly beyond apex of ventral process. Description. Body length 5.1 mm; forebody length 2.7 mm. Body (Fig. 1D) reddish brown; antennae and legs yellowish brown. Head (Fig. 5A) 1.02 times as long as wide; punctation dense and coarse, distinctly umbilicate and partly confluent, interstices lacking microsculpture; postocular portion approximately 2.13 times as long as eye length. Pronotum (Fig. 5A) 1.09 times as long as wide, 0.97 times as long and 0.91 times as broad as head; punctation non-umbilicate, moderately dense and less coarse than that of head; midline posteriorly with short and narrow impunctate elevation; interstices lacking microsculpture. Elytra (Fig. 5A) 0.64 times as long as wide, 0.56 times as long and 0.95 times as broad as pronotum; punctation more dense and less coarse than that of pronotum; interstices lacking microsculpture. Abdomen with punctation dense and rather coarse on tergites III–IV, dense and less coarse on tergite V, moderately dense and fine on tergites VI–VIII; interstices lacking microsculpture. Male. Sternite VII (Fig. 5B) with posterior margin slightly prominent at middle, with dense and dark setae near emargination. Sternite VIII (Fig. 5C) with wide V-shaped posterior excision. Aedeagus (Figs 5D–G) well sclerotized; ventral process long, with drop-shaped cavity in middle in ventral view, strongly curved dorsad at apex in lateral view; dorso-lateral apophyses long, with small and dense sawteeth at basal half of lateral margin in ventral view, distinctly expanded near apex in ventral and lateral view, extending slightly beyond apex of ventral process. Distribution and habitat data. The species is known only from Wumengshan N. R. in northeast Yunnan. The specimen was collected by sifting leaf litter at an altitude of 1709 m. Comparative notes. The new species is very similar to N. guohaoi in general appearance and separated by the following characters: male sternite VII with posterior margin slightly prominent at middle (Fig. 5B); ventral process of aedeagus with drop-shaped cavity in the middle in ventral view (Figs 5D, 5E) and strongly curved dorsad at apex in lateral view (Figs 5F, 5G); dorso-lateral apophyses with sawteeth at basal half of lateral margin in ventral view (Figs 5D, 5E). Etymology. The specific epithet is composed of the Latin words ‘serratus’ and ‘marginatus’, indicating the serrated dorso-lateral apophyses of the aedeagus.