Two new species of the genus Gonioctena Chevrolat(Coleoptera, Chrysomelidae, Chrysomelinae) from Sichuan, China

摘要

Two new species of Gonioctena Chevrolat, G. sickuana sp. n. and G. metallica sp. n., are described from Sichuan Province. China. Diagnostic characters and illustrations are provided. Ovoviviparity is recorded in G. metallica sp. n.The genus Gonioctena Chevrolat, 1836 is widely distributed in the Holarctic and Oriental regions. Members of the genus are characterized by mandibles generally with a large excavation at outer side, elytral epipleura slanted downward, procoxal cavities opened posteriorly, tibiae generally with a preapical tooth, third tarsomere not bilobed and tarsal claws appendiculate. Adults of the genus are greatly diverse in colouration even within a species and similar in external morphology. Therefore, several available keys and regional reviews of the group depend heavily on the male genitalia, for example, Europe (Warchalowski 2003), Russia (Medvedev 1992), China and Korea (Gressit & Kimoto 1963) and Japan (Takizawa 2007). To date, 84 species have been reported in the Palaearctic region (Cho & Lee 2010; Kippenberg 2010; Suenaga 2012), of which 29 species occur in China (Ge et al. 2007). During our study on the Chinese Gonioctena species, we found two new species from Sichuan Province, which are described below. Photographs, illustrations and diagnostic characters are provided.