Prosthecarthron insulanus Yin and Huang

Yin, Zi-Wei, Huang, Shao-Bin & Gu, Fu-Kang, 2012, Notes on Prosthecarthron Raffray, with description of P. insulanus, sp. n. (Coleoptera, Staphylinidae, Pselaphinae) from Qi’ao Island, South China, Zootaxa 3530, pp. 83-88 : 85-86

Prosthecarthron insulanus Yin and Huang , new species

( Figs 1 A, 2, 3)

Type-locality. South China: Guangdong Province, Zhuhai City, Qi’ao Island, 22°25ʹ12.43ʺN, 113°38ʹ0 5.39ʺE, 5 m a.s.l.

Type material (31 33). Holotype: CHINA: 3, labeled ‘ China: Guangdong / Zhuhai, Qi’ao Island / mangrove forest / 3.vi.2012 (light trap) / Shao-Bin Huang leg. // HOLOTYPE [red] / Prosthecarthron insulanus sp. n. / Yin & Huang / det. 2012, SNUC’. Paratypes: CHINA: 30 33, same label data as holotype, with the following paratype label: ‘ PARATYPE [yellow] / Prosthecarthron insulanus sp. n. / Yin & Huang / det. 2012, SNUC’.

Description. Male. Length 1.94–2.07; body ( Fig. 1 A) reddish brown, maxillary palpi and tarsi lighter; densely covered with short pubescence. Head transverse, wider than long, HL 0.39–0.40, HW 0.45–0.46. Eyes each composed of about 35 large facets. Antennal club loosely three-segmented, segment V ( Fig. 2 A) strongly modified. Pronotum rounded laterally, wider than long, PL 0.42–0.45, PW 0.48–0.49. Elytra wider than long, EL 0.59–0.62, EW 0.74–0.78. Protrochanters ( Fig. 2 B) spinose on ventral margins; protibiae with small apical tubercle; mesotrochanters ( Fig. 2 C) with small ventral tubercle, mesotibiae with large apical spur; metatrochanters ( Fig. 2 D) with blunt ventral tubercle; metatibiae broadly expanded mesally and serrate ( Fig. 2 E) on mesal margin near middle. Abdomen about same width as elytra, AL 0.54–0.60, AW 0.68–0.71; tergite IV as long as next two segments combined; tergite VIII ( Fig. 2 F) and sternite VIII ( Fig. 2 G) transverse; sternite IX ( Fig. 2 H) paired. Aedeagus ( Fig. 2 I) length 0.31, well-sclerotized, median lobe narrowed apically.

Female. Unknown, probably with simple antennae and legs.

Distribution. Presently known only from the type locality in Guangdong ( Fig. 3 ).

Biology. Individuals were collected by a light trap set near a mangrove forest.

Comparative notes. The new species is closely related to P. sauteri in sharing a nearly identical antennal modification in the male. The two species can be readily separated by the mesotibiae with a long apical spur on the mesal margin and the metatibiae with serrate mesal margin near the middle in P. insulanus . Prosthecarthron sauteri has the mesotibiae lacking an apical spur and the metatibiae are smooth on the mesal margin. The other species of the genus, P. frontalis , differs from both P. insulanus and P. sauteri by the frons with a large cavity in the male.

Etymology. The Latin word ‘ insulanus ’ means ‘an inhabitant of an island’, indicating the new species was taken from an island.

Figures

FIGURE 1. Dorsal habitus of P. insulanus (1) and P. sauteri (2). Scales: 0.5 mm.

FIGURE 2. Diagnostic features of P. insulanus. A. Antennal modification. B. Proleg. C. Mesoleg. D. Metaleg. E. Metatibia, enlarged. F. Male tergite VIII. G. Male sternite VIII. H. Male sternite IX. I. Aedeagus, in dorsal view. Scales: A – E = 0.2 mm, F – I = 0.1 mm.

FIGURE 3. Distribution of Prosthecarthron species (data of P. sauteri and P. frontalis were collected from respective references).