A Review of the Leaf-Beetle Genus Aulacolepis Baly, 1863 (Coleoptera, Chrysomelidae: Eumolpinae)

An emended description of the genus Aulacolepis is given, and the taxonomic status, diagnostic characters, and geographical distribution of its representatives are clarified. Two species groups which differ in the degree of dilation of the lateral margins of the elytra and in the density of the scales covering the dorsal side of the body are distinguished. The representatives of the mouhoti species-group distributed in mainland Indochina, the Malay Peninsula, and some adjacent islands have sparse scales on the dorsal side of the body and narrow lateral margins of the elytra. The species of the decorata group from Singapore and the Greater Sunda Islands have denser scales on the dorsal side of the body and widely flattened lateral margins of the elytra. Two new species of this genus have been described: Aulacolepis malayana sp. n. inhabiting the Malay Peninsula and adjacent islands (including Phuket) and belonging to the mouhoti species group, and the Bornean Aulacolepis borneensis sp. n. from the decorata species group. Aulacolepis decorata Baly, 1867 is recorded for Singapore and Java for the first time. An identification key is compiled for all the species of the genus, and photographs of the beetles and their genitalia are provided for the first time.