A new genus of Blattisociidae (Acari: Mesostigmata: Phytoseioidea) from Australian burrowing carabid beetles

Krantzoseius walteri gen. nov., sp. nov. (Mesostigmata: Phytoseioidea: Blattisociidae: Blattisociinae) is described from female, male, deutonymphal, protonymphal and larval specimens collected from Trichosternus perater Sloane (Coleoptera: Carabidae: Pterostichini) in South East Queensland, Australia. The family assignment of the new species is tentative and is based largely on its lack of the apomorphic characters that define the other phytoseioid families (Otopheidomenidae, Phytoseiidae and Podocinidae). Its highly hypotrichous body, reduced body shields and leg chaetotaxy are especially unusual, and although similar to the Otopheidomenidae in these characters, K. walteri lacks the adaptations to parasitism that define the Otopheidomenidae. Curiously, the opisthosomal chaetome of the larvae (12 pairs of setae plus postanal seta) is richer than that of the protonymph (nine pairs of setae plus postanal seta), representing a rare example of postlarval setal suppression.