The frog-biting midges of Borneo-from two to eleven species (Corethrellidae: Diptera)

Abstract

The Corethrella Coquillett of Borneo are described and interpreted, based primarily on material from Brunei Darussalam and a few locations in the Malaysian states of Sarawak and Sabah. The eleven species include three previously named (one newly discovered in Borneo) and eight newly named species. The following new species are attributed to Borkent & Grafe: C. lutea, C. tigrina, C. gilva, C. nanoantennalis, C. mitra and C. bipigmenta. Two new species, C. bicincta and C. unizona are attributed to Borkent, Grafe & Miyagi. Of the eleven Bornean species, 10 are recorded from Brunei Darussalam and eight of these are also known from at least Sarawak. This distribution of species as well as comparison of species collected directly from calling frogs with those collected with frog-call traps (some with modified sound) indicate that diversity is not as high as in Central America (the only other tropical area intensely sampled). Surveys of aquatic habitats show that Corethrella are absent from phytotelmata (water bodies held by plants) in Borneo, other than C. calathicola Edwards which is present in some species of Nepenthes and a species most closely related to a relatively derived group of Neotropical species occupying treeholes (C. calathicola likely dispersed from the Neotropical Region). Phylogenetic analysis indicates that, other than C. calathicola, species are members of an early lineage called the drakensbergensis species group (n = 6), is the sister group of a large assemblage of Old and New World species (n = 1) or cannot be placed phylogenetically (probably because of lack of immatures and males) (n = 3). Copyright © 2012 · Magnolia Press.