Heminothrus

van der Hammen, L., 1959, Berlese's Primitive Oribatid Mites, Zoologische Verhandelingen 40, pp. 1-93 : 69

Heminothrus Berlese, 1913

Heminothrus Berlese, 1913, p. 98.

Heminothrus was described as a subgenus of Nothrus (i.e. Camisia ). Berlese gave a concise diagnosis, and designated Nothrus Targionii Berlese (1885a) as type. It is remarkable that no diagnosis was given of the genus Platynothrus (same paper, p. 99!), although the two genera are closely related. In fact it is difficult to give diagnostic characters of Heminothrus and Platynothrus . Sellnick & Forsslund (1955) separated the genera on account of the presence of sacculae attached to the bothridium; the use of this character results in a genus Platynothrus that contains a heterogeneous collection of species.

I have contributed the species with distinct dorsal ridges, which have a rather similar habitus, to the genus Platynothrus . The remaining species are listed with Heminothrus ; this genus certainly must be divided into a number of genera. I remark that H. capillatus has faint dorsal ridges in the anterior part of the notogaster (and short sensilli); H. thori is different because of the completely scleritized coxisternal region. For a future subdivision it will be useful to pay attention to position and length of the notogastral hairs; further to cerotegument, secretion, and adhering dirt.