The earwig (Dermaptera) fauna of Penang Island, Malaysia, was evaluated by means of an extensive field survey together with revision of the few published data. Based on the results of the field survey, 31 species are recognized (2 Diplatyidae, 3 Pygidicranidae, 5 Anisolabididae, 2 Labiduridae, 14 Spongiphoridae, 4 Chelisochidae, 1 Forficulidae). Fifteen of these taxa are new to Peninsular Malaysia (=West Malaysia): Diplatys annandalei Burr, 1911, Diplatys mutiara n. sp., Euborellia philippinensis Srivastava, 1979, Metisolabis punctata (Dubrony, 1879), Pseudovostox brindlei Srivastava, 2003, Chaetospania anderssoni Brindle, 1971, Chaetospania javana Borelli, 1926, Chaetospania huisiangi n. sp., Paralabellula boettcheri (Borelli, 1923), Paralabellula rotundifrons (Hincks, 1954), Nesogaster amoenus (Stål, 1855), Hamaxas crassus Borelli, 1926, Proreus coalescens (Borelli, 1927), Hypurgus humeralis (Kirby, 1891), and an unidentified Echinosoma sp. Species composition of the island are compared with the dermapteran fauna of Thailand. Descriptions of females (or female genitalia) are given for some species for the first time.
Euborellia (Anisolabididae: Anisolabidinae) is one of the most speciose genera of earwigs (Dermaptera), and its species-level classification is difficult. To settle the classification of brachypterous species with abbreviated tegmina recorded from East and Southeast Asia, we examined the morphology and reproductive isolation of three tentative Euborellia species, and analyzed the DNA barcoding region of the mitochondrial cytochrome oxidase subunit I (COI) gene. The observed complete reproductive isolation among the three Euborellia taxa and considerable differentiation in the COI sequences clearly show that each should be treated as a separate species. Based on morphology, distribution and the DNA sequence, we identify Euborellia sp. 1 of Malaysia as E.annulata (Fabricius), a circumtropical cosmopolitan with no records of a fully winged form. Samples from Ioto Island (= Iwo-jima Island: Ogasawara Islands, southern Japan) were also identified as this species. Euborellia sp. 3, from the main islands of Japan, was generally larger and lacked a Y-shaped pigmented area on the penis lobe, which is characteristic of Euborellia sp. 1. We propose reinstating E.pallipes (Shiraki) as the oldest name for this taxon. Euborellia sp. 2, even the brachypterous form, can be distinguished from these two species by its paler coloration (particularly the femora), ecarinate post-abdomen, and the shape of the male genitalia (parameres). We tentatively identify this species as E.philippinensis Srivastava based on the morphology of the brachypterous form, although the macropterous form cannot be distinguished from E.femoralis (Dohrn).