The Muscidae (Diptera) of New Caledonia 2503 Author Couri, Marcia S. Author Pont, Adrian C. Author Daugeron, Christophe text Zootaxa 2010 2010-06-11 2503 1 1 61 https://biotaxa.org/Zootaxa/article/view/zootaxa.2503.1.1 journal article 10.11646/zootaxa.2503.1.1 1175­5334 10094189 Genus Dichaetomyia Malloch Dichaetomyia Malloch, 1921a: 163 . Type-species: Dichaetomyia polita Malloch, 1921 [preocc., = Dichaetomyia emdeni Pont, 1969 ], orig. des. Diagnosis. Eyes of male narrowly separated by the diameter of anterior ocellus or more; eyes in female widely separated; proclinate orbital and crossed setae on frontal vitta absent; arista long-plumose; dorsocentrals 2+2, 3 or 4, the first presutural seta shorter than the second; prosternum setulose on sides; anepimeron setulose; prealar seta present; postalar wall with sparse hairs or bare; posterior spiracle with some black setulae along lower margin; vein M only slightly curved forwards before apex; hind tibia with a well developed anterodorsal preapical in addition to dorsal one, calcar absent. Comments. Dichaetomyia is abundantly represented in the Australasian/Oceanian Regions, with 72 species ( Pont, 1989 ). Two species have been recorded from New Caledonia : D. bilimbata ( Bigot, 1885 ) , described from New Caledonia , and “ Dichaetomyia sp. polita -group”, listed by Shinonaga et al. (1991) which we describe here as new. Both species are endemic and belong to the polita -group (see Pont, 1969a ). Nine species belonging to this group have been described from the Oriental and Australasian Regions. Six of these are from Malaysia and the Philippines , and two are from New Guinea ( D. polita (Stein) and D. nigrolineata (Stein) , the latter endemic so far as is known). Pont (1969a) described D. collessi from Australia ( Queensland ) which, according to him, “occupies a rather isolated position amongst Australian Dichaetomyia ”, being most closely related to the New Guinea D. polita . Both New Caledonian species belong to the polita -group and share the following characters: male with two pairs of tiny reclinate orbital setae, and female with one strong pair of frontals near lunule and a weak pair above this; presutural acrostichal setae arranged in 9 to 10 series; dorsocentrals 2+3, the first presutural at least half as long as the posterior pair; meron bare but with fine hairs on metepisternum above hind coxa; anatergite bare; fore tibia with a submedian posterior seta; lower calypter bare on disc. Dichaetomyia species , and especially D. bilimbata , appear to be by far the dominant muscid populations on the island and were mainly collected at Rivière Bleue.