The Nazeris fauna of the Nanling Mountain Range, China (Coleoptera, Staphylinidae, Paederinae)

Abstract Fourteen species of Nazeris Fauvel, 1873 are reported for the Nanling Mountain Range, China. Four of them are described as new: N.xingmini Lin & Hu, sp. nov. (Guangdong, Jiangxi), N.huaiweni Lin & Hu, sp. nov. (Guangdong), N.meihuaae Lin & Hu, sp. nov. (Guangdong, Jiangxi) and N.lichongi Lin & Hu, sp. nov. (Hunan). An identification key to the Nazeris species reported for the Nanling Mountains, and a map showing their distribution are provided.

Distribution and habitat data. The species is known only from Huaping in northeast Guangxi (Fig. 27). The specimens were collected by sifting leaf litter at altitudes of 1700-1800 m.

Nazeris huapingensis Hu & Li, 2017
Comparative notes. Nazeris huapingensis is very similar to N. obtortus Assing, 2016 from the same locality in general appearance and separated only by aedeagal characters: the apex of the ventral process in ventral view is much broader; apices of the dorso-lateral apophyses rounder and broader (Hu and Li 2017: 336, fig. 13).

Nazeris latilobatus
Comparative notes. Nazeris latilobatus is similar to N. qini Hu & Li, 2012 from Dayaoshan in external and the male sexual characters, but can be separated by the deeper posterior excision of the male sternite VIII (Assing 2016: 307, fig. 9), and the much broader apex of the aedeagal ventral process (Assing 2016: 307, fig. 11).
Distribution and habitat data. The species is known only from Mao'ershan in northeast Guangxi (Fig. 27). The specimen was collected by sifting leaf litter at altitudes of 450-2040 m.
Comparative notes. Nazeris nanlingensis is very similar to N. rubidus Hu, Luo & Li, 2018a from the same locality in general appearance and aedeagal characters, but can be separated by the smaller forebody size; less dense punctation of the head and pronotum (Hu et al. 2018a: 177, fig. 14); a wider ventral process and slenderer dorso-lateral apophyses of the aedeagus in ventral view (Hu et al. 2018a: 177, fig. 17).

Nazeris obtortus
Comparative notes. Nazeris obtortus is quite similar to N. huapingensis and separated only by aedeagal characters: the apex of the ventral process and apices of the dorso-lateral apophyses are much narrower (Assing 2016: 309, fig. 16).
Distribution and habitat data. The species is known only from Huaping in northeast Guangxi (Fig. 27). The specimens were collected by sifting leaf litter at altitudes of 820-1200 m.
Comparative notes. Nazeris rubidus is very similar to N. huapingensis in general appearance and aedeagal characters, but can be separated by the following combination of characters: the posterior excision of the male sternite VIII is wider (Hu et al. 2018a: 176, fig. 11); the apex of the ventral process of the aedeagus is widely rounded in ventral view (Hu et al. 2018a: 176, fig. 12); the dorso-lateral apophyses is nearly straight in lateral view (Hu et al. 2018a: 176, fig. 13).
Distribution and habitat data. The species is known from Nanling in northern Guangdong and Mangshan in southern Hunan (Fig. 27). The specimens were collected by sifted leaf litter at altitudes of 700-1820 m. Comparative notes. Nazeris rugosus is distinguished from all the known species of Nazeris from the Nanling Mountains by the microsculpture covering the head, pronotum and abdomen (Hu and Qiao 2019: 436, figs 18-20), and by the distinctive shape of the aedeagus, particularly the apically narrowed ventral process (Hu and Qiao 2019: 436, fig. 23).

Nazeris rugosus Hu & Qiao, 2019
Distribution and habitat data. The species is known only from Mao'ershan in northeast Guangxi (Fig. 27). The specimen was collected by sifting leaf litter at altitudes of 1990-2100 m. Comparative notes. Nazeris yanzhuqii is most similar to N. alatus in general appearance and aedeagal characters, but can be separated by the impunctate elevation of the pronotum very narrow or absent (Hu and Qiao 2019: 438, fig. 35), by the longer and wider ventral process of the aedeagus in ventral view, with much smaller basal laminae, and by the wider dorso-lateral apophyses of the aedeagus (Hu and Qiao 2019: 438, fig. 38).

Nazeris yanzhuqii Hu & Qiao, 2019
Distribution and habitat data. The species is known only from Mao'ershan in northeast Guangxi (Fig. 27). The specimen was collected by sifting leaf litter at altitudes of 1940-2140 m. Distribution and habitat data. The species is known only from Mao'ershan in northeast Guangxi (Fig. 27). The specimen was collected by sifting leaf litter at altitudes of 1143-1660 m. Description. Body length 6.4-7.5 mm; forebody length 3.2-3.4 mm. Body ( Fig. 1) dark brown; legs yellowish brown; antennae dark brown to light brown. Head (Fig. 5) 1.02-1.12 times as long as wide; punctation very dense, moderately coarse, non-umbilicate, interstices lacking microsculpture; postocular portion approximately 1.6-2.1 times as long as eye length. Pronotum (Fig. 5) 1.18-1.22 times as long as wide, 0.95-1.02 times as long and 0.83-0.91 times as broad as head; punctation non-umbilicate, moderately dense and as coarse as that of head; midline posteriorly with short and very narrow impunctate elevation; interstices lacking microsculpture. Elytra (Fig. 5) 0.59-0.67 times as long as wide, 0.50-0.57 times as long and 0.96-1.09 times as broad as pronotum; punctation as dense as, and slightly coarser than that of pronotum; interstices lacking microsculpture.

Nazeris xingmini
Abdomen with punctation dense and rather coarse on tergites III-V, dense and less coarse on tergite VI, moderately dense and fine on tergites VII-VIII; interstices lacking microsculpture.
Male. Sternite VII ( Fig. 6) with posterior margin truncate at middle. Sternite VIII (Fig. 7) with wide triangular posterior excision. Aedeagus (Figs 8, 9) well sclerotized; with ventral process narrowed near middle in ventral view, with U-shaped excision at apex in ventral view, with pair of wing-like basal laminae ventrally; dorso-lateral apophyses moderately strong, distinctly curved in ventral view, curved dorsally and slightly widened at apices in lateral view, extending beyond apex of ventral process. Distribution and habitat data. The species is known from Chebaling in northern Guangdong and Jiulianshan in southern Jiangxi (Fig. 27). The specimens were collected by sifting leaf litter at altitudes of 357-587 m.
Comparative notes. The new species is very similar to N. inaequalis Assing, 2014 in general appearance and separated only by the aedeagal characters: the apex of the ventral process is symmetric in ventral view (Fig. 8); dorso-lateral apophyses extending beyond the apex of the ventral process.
Etymology. The species is named in honor of Xing-Min Wang (South China Agricultural University) who helped a lot during our collection in Nanling. Description. Body length 6.2-6.8 mm; forebody length 3.2-3.3 mm. Body (Fig. 2) dark brown; antennae and legs yellowish brown. Head (Fig. 10) approximately as long as wide; punctation very dense, moderately coarse, distinctly umbilicate, interstices lacking microsculpture; postocular portion approximately twice as long as eye length. Pronotum (Fig. 10) 1.12-1.21 times as long as wide, 0.93-1.02 times as long and 0.83-0.84 times as broad as head; punctation non-umbilicate, moderately dense and as coarse as that of head; midline posteriorly with short and very narrow impunctate elevation; interstices lacking microsculpture. Elytra (Fig. 10) 0.67-0.76 times as long as wide, 0.69-0.71 times as long and 1.03-1.12 times as broad as pronotum; punctation slightly denser and coarser than that of pronotum; interstices lacking microsculpture.

Nazeris huaiweni
Abdomen with punctation dense and rather coarse on tergites III-V, dense and less coarse on tergite VI, moderately dense and fine on tergites VII-VIII; interstices lacking microsculpture.
Male. Sternite VII (Fig. 11) with posterior margin truncate at middle. Sternite VIII (Fig. 12) with triangular posterior excision. Aedeagus (Figs 13, 14) with ventral process gradually narrowed in apicad half, with acute apex in ventral view or lateral view, with pair of wing-like basal laminae ventrally; dorso-lateral apophyses moderately slender, slightly widened near middle and apices in ventral view, not reaching apex of ventral process.
Distribution and habitat data. The species is known only from Nanling in northern Guangdong (Fig. 27). The specimens were collected by sifted leaf litter at altitudes of 1270-1575 m.
Comparative notes. The new species is very similar to N. divisus Hu & Li, 2015 in general appearance, but can be separated by the wider and shallower posterior excision of male sternite VIII (Fig. 12), by the ventral process with acute apex (Fig. 13), and by the wider dorso-lateral apophyses of aedeagus (Fig. 13).
Etymology. The species is named in honor of Huai-Wen Wang (Administration of Nanling National Nature Reserve) who helped a lot during our collection in Nanling.   Head (Fig. 15) 0.97-1.03 times as long as wide; punctation very dense, moderately coarse, distinctly umbilicate and partly confluent, interstices lacking microsculpture; postocular portion approximately 1.5-2.1 times as long as eye length. Pronotum (Fig. 15) 1.05-1.23 times as long as wide, 0.91-1.10 times as long and 0.83-0.87 times as broad as head; punctation non-umbilicate, moderately dense and as coarse as that of head; midline posteriorly with short and very narrow impunctate elevation; interstices lacking microsculpture. Elytra (Fig. 15) 0.61-0.75 times as long as wide, 0.54-0.66 times as long and 0.97-1.10 times as broad as pronotum; punctation as dense as, and slightly coarser than that of pronotum; interstices lacking microsculpture.

Nazeris meihuaae
Abdomen with punctation dense and rather coarse on tergites III-V, dense and less coarse on tergite VI, moderately dense and fine on tergites VII-VIII; interstices lacking microsculpture.
Male. Sternite VII (Fig. 16) with posterior margin shallowly emarginate in the middle. Sternite VIII (Fig. 17) with wide triangular posterior excision. Aedeagus  with ventral process short, widened near middle in ventral view, with pair of finger-like basal laminae ventrally; dorso-lateral apophyses distinctly curved and widened in apical third in ventral view, extending beyond apex of ventral process.
Distribution and habitat data. The species is known from Chebaling in northern Guangdong and Jiulianshan in southern Jiangxi (Fig. 27). The specimens were collected by sifting leaf litter at altitudes of 468-1253 m.
Comparative notes. This species is very similar in general appearance and aedeagal characters to N. pengzhongi Hu & Li, 2015, but can be separated by the finger-like basal laminae of the ventral process and the longer dorso-lateral apophyses of the aedeagus (Figs  18, 20). The new species is also similar in general appearance to N. rubidus and N. nanlingensis, but can be separated by the distinctly longer laminae of the ventral process and the apically wider dorso-lateral apophyses of the aedeagus (Figs 18, 20). Compared with the holotype from Chebaling, Guangdong (Figs 18, 19), the specimens from Jiulianshan, Jiangxi (Figs 20, 21) display a slightly shorter ventral process and slightly narrower apices of the dorso-lateral apophyses of the aedeagus. Based on the similar general appearance and male sternites, these aedeagal differences are treated as intraspecific variation.
Etymology. The species is named in honor of Mei-Hua Xia, who collected some of the type specimens. Description. Body length 4.7 mm; forebody length 2.4 mm. Body (Fig. 4) reddish brown; antennae and legs yellowish brown. Head (Fig. 22) 0.97 times as long as wide; punctation very dense, moderately coarse, distinctly umbilicate and partly confluent, interstices lacking microsculpture; postocular portion approximately 1.6 times as long as eye length. Pronotum (Fig. 22) 1.17 times as long as wide, as long as and 0.83 times as broad as head; punctation non-umbilicate, moderately dense and as coarse as that of head; midline posteriorly with short and very narrow impunctate elevation; interstices lacking microsculpture. Elytra (Fig. 22) 0.77 times as long as wide, 0.66 times as long and as broad as pronotum; punctation as dense as, and slightly coarser than that of pronotum; interstices lacking microsculpture.

Nazeris lichongi
Abdomen with punctation dense and rather coarse on tergites III-V, dense and less coarse on tergite VI, moderately dense and fine on tergites VII-VIII; interstices lacking microsculpture.
Male. Sternite VII (Fig. 23) with posterior margin shallowly emarginate in the middle. Sternite VIII (Fig. 24) with triangular posterior excision. Aedeagus (Figs 25,26) with broad ventral process, slightly widened in apical half, with round apex in ventral view, with pair of heart-like basal laminae; dorso-lateral apophyses slender, distinctly curved in ventral view, curved dorsally and slightly widened at apices in lateral view, extending beyond apex of ventral process.
Distribution and habitat data. The species is known only from Dupangling in southern Hunan (Fig. 27). The specimen was collected by sifting leaf litter at an altitude of 448 m.
The new species is similar in general appearance and aedeagal characters to N. rubidus and N. nanlingensis, but can be separated by the slightly dorsally curved dorso-lateral apophyses of the aedeagus in lateral view (Fig. 26), and by the heart-like basal laminae of the ventral process (Fig. 25).