Studies on the taxonomy and biology of the subfamily Trombidiinae (Acarina : Trombidiidae) with a critical revision of the genera

Abstract

The subfamily Trombidiinae Thor. 1935 in the acarine family Trombidiidae, with a world-wide distribution. is critically reviewed and redefined . In previous classifications. based largely on adults. the affinities of several genera were obscured by the convergent morphology of their adult instars . The number of genera known as larvae is now increased from three to seven. The following genera are recognized: Pollicotrombium. gen . nov., type-species Caenothrombium miniatum Womersley (1 sp.); Austrothrombium Womersley (7 spp.); Caenothrombium Oudemans; Xenothrombium Oudemans (1 sp.); Dinothrombium Oudemans (= Angelothrombium Newell & Tevis as adult; = Isothrombium Andrk as larva); Clinotrombium, gen. nov., type-species C. antares, sp. nov. (4 spp.); Nippotrombium, gen. nov., type-species N. kekko, sp. nov. (1 sp.); Acritrombium, gen. nov., type-species A. striatum, sp. nov. (1 sp.); Paratrombium Bruyant (6 spp. of larvae); Trombidium Fabricius ( = Sericothrombium Berlese; = Holothrombium Feider, as adult; = Metathrombium Oudemans, as larva; ? = Atomus Latreille, as larva), with subgenera Trombidium and Teresothrombiurn Feider; Archithrombium Feider; Dolichothrombium Feider. The following new species are described: Austrothrombium scaurum (ad., Australian Capital Territory); A. mullewaense (ad., Western Australia); A. porongorense (ad., Western Australia); Clinotrombium antares (larva, on spider, South Australia); C. bellator (larva, on spiders, South Australia); C. commoni (larva, on noctuid moth, Australian Capital Territory); C. dumosum (larva, on noctuid moth, ?Mauritius); Nippotrombium kekko (larva, on noctuid moth, Japan); Acritrombium striatum (larva, on tetrigid grasshoppers Paratettix spp., Queensland); Trombidium (Teresothrombium) breei (larva, on satyrid butterfly, Britain and Europe).

The larva, egg and deutovum of Pollicotrombium miniatum are described. The adults of Austrothrombium australiense (Hirst), A. hirsutum (Womersley), A. insigne (Hirst) and A. kondininum (Hirst) are redescribed. Keys are provided for adults and/or larvae where appropriate. Beronium, gen. nov., is erected for Hoplothrombium coiffati Beron (larval) (Microtrombidiinae) from Morocco.