Prosthecarthron Raffray, 1914

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 : 84

Prosthecarthron Raffray, 1914

Type species. Prosthecarthron sauteri Raffray, 1914: 3 (by original monotypy)

Diagnostic combination. Head with punctiform vertexal foveae; antennal clubs loosely formed by apical three antennomeres; ventrolateral margins of head rounded beneath eyes; distinct median gular carina broad. Pronotum with small nude lateral antebasal foveae, lacking median antebasal fovea. Elytra with two basal foveae, with elongate discal striae. Tergite IV lacking basal impression and mediobasal foveae; sternite IV nearly flat at base.

Redescription. Length 1.55–2.07 [cleared specimen of P. sauteri and P. insulanus examined]. Head transversely rectangular; with small nude vertexal foveae; frontal rostrum prominent, antennal tubercles low; with 11 antennomeres, clubs loosely formed by apical three antennomeres; ocular-mandibular carinae present; ventral lateral margins lacking carinae; small gular foveae widely separated, gular carina broad. Pronotum transverse, with round lateral margins; lacking median antebasal fovea, with nude lateral antebasal foveae; paranotal carinae extending from pronotal base to above procoxae; lateral procoxal foveae widely separated. Each elytron with two basal foveae; discal striae converging, extending nearly to elytral apex. Thorax with median mesoventral foveae in large opening, broadly forked; lateral mesoventral foveae large; lateral mesocoxal foveae present; with lateral metaventral foveae. Abdomen with tergite IV longest, about as long as next two segments combined; tergite IV with base flat, with long discal carinae, lacking mediobasal foveae, basolateral foveae present; tergites IV–VII with complete paratergites; sternite IV lacking basolateral sulci, mediobasal foveae present. Pro- and meso-pair of tarsi with third tarsomeres slightly shorter than second tarsomeres; meta-pair of tarsi with third tarsomeres half length of second tarsomeres; tarsal claws long. Males with frons, antennae, and apices of tibiae or metatibiae modified. Aedeagus symmetric; with reduced parameres; dorsal diaphragm present.

Natural history. As far as is known adults of this genus are commonly found from wetlands in the estuaries of rivers ( Nomura 1998, Arai et al. 2005), and under stones lying on salt meadow plants ( Löbl 1977), or on mud flat along mangrove seashores ( Park et al. 2011). Males of this genus are often attracted by light trap.

Comparative notes. Raffray stated (1914: 3) that ‘ Prosthecarthron is placed with Pedinopsis Raffray (now Pedisinops Newton & Chandler, 1989 )’. These two genera share a more or less parallel body form, the presence of two basal elytral foveae, the elongate elytral discal striae, and the long prominent discal carinae on the abdominal tergite IV. Prosthecarthron lacks a median antebasal fovea on the pronotum, and has the abdominal tergite IV being flat at base and lacking mediobasal foveae, while Pedisinops has a setose pronotal median antebasal fovea, and the abdominal tergite IV has mediobasal foveae at lateral margins of the setose impression.