Morphology of three species of Crotonioidea Thorel, 1876 (Acari: Oribatida), and relations between some genera

The morphology of juveniles of Archegozetes longisetosus Aoki, 1965 (Trhypochthoniidae), and two members of Malaconothridae, Trimalaconothrus angulatus Willmann, 1931, and Malaconothrus monodactylus (Michael, 1888) is described and illustrated, and the tritonymph of A. longisetosus and all juvenile stages of T. angulatus are described and illustrated for the first time. The juveniles of these species differ mainly by the presence of setae f₂ and h₃ in the larva, seta exs and pattern of cuticle in the nymphs, and some setal formulae. Based on the morphology of juvenile stages and adults, the relationship between Malaconothridae and Trhypochthoniidae is discussed, and keys to the larvae and nymphs of some European species of these families are presented.