56 Accepted by J. Martin: 2 May 2012; published: 26 Jun. 2012 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2012 · Magnolia Press Zootaxa 3357: 56–62 (2012) www.mapress.com/ zootaxa/ Article The Stenchaetothrips species (Thysanoptera, Thripidae) of Malaysia, with one new species NG, Y.F. 1 & MOUND, L.A. 2 1 Centre for Insect Systematics (CIS), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia. E-mail: ng_yf@ukm.my 2 CSIRO Ecosystem Sciences, PO Box 1700, Canberra, ACT 2601, Australia. E-mail: laurence.mound@csiro.au Abstract Four species of Stenchaetothrips are here recorded from Peninsular Malaysia. These are S. biformis, the widespread rice thrips, S. hullikali, known only from Karnataka in Southwest India, S. indicus, a widespread species on grasses, and S. langkawiensis sp. nov., described here from Langkawi Island, West Malaysia. Species descriptions, photographs and an identification key are provided. Key words: Thysanoptera, Stenchaetothrips, Malaysia, new species, new records Introduction The genus Stenchaetothrips Bagnall, comprising a group of Poaceae-living species, is closely related to the genus Thrips. These two genera belong to a genus-group of Thripinae that exhibit the important synapomorphy of the ctenidia on abdominal tergite VIII being situated postero-mesad to the spiracles (Mound 2002). Moreover, all of the species in this group lack a pair of setae on the head immediately anterior to the first ocellus (ocellar setal pair I). In Stenchaetothrips the adults bear a pair of unusually long setae anterolateral to the first ocellus (ocellar setal pair II), and these setae are always longer than ocellar setal pair III, which are associated with the ocellar triangle. The postocellar setae I and III of these thrips are both usually very long, and the metascutum is sculptured with closely-spaced longitudinal striations. Stenchaetothrips species are found predominantly in Asia, but a few have become distributed worldwide (Mound & Ng 2009; Mound 2011). Only the rice thrips, S. biformis (Bagnall), has previously been recorded from Malaysia, although so far it has not been regarded as a major pest on paddy in this country (Talekar 1991; Pathak & Khan 1994; Saiful Zaimi J., MARDI entomologist , personal communication, 2011). Currently the genus includes 33 species (Mound 2012). A full account of 15 Stenchaetothrips species known from India was provided by Bhatti (1982), but Tyagi & Kumar (2008) subsequently described two further new species from that country. Wang (2000) provided a key to eight species of the genus from Taiwan; zur Strassen (1994) listed four species from Indonesia; Reyes (1994) treated three species from the Philippines, and Mound (2011) three species from Australia. In this paper, four species are recorded from Peninsular Malaysia, including one species new to science and two new country records. Among the known species of this genus, the new species shares only with S. indicus the absence of a comb of long regular microtrichia on the posterior margin of the eighth abdominal tergite. Females of this new species have a comb of irregular, short, rather dentate teeth on tergite VIII, whereas in S. indicus there is no comb at all. Nomenclatural details of all the taxa discussed here are available in Mound (2012). Key to Stenchaetothrips from Malaysia 1. Body pale yellow (Fig. 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 -. Body either uniformly brown or bicoloured (Figs 12, 19) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3