No abstract

A population genetic study of Halotydeus destructor (Tucker) and H. anthropus Qin & Halliday was undertaken using allozyme electrophoresis. Allele frequency data were collected from five polymorphic loci {Gpi -glucose phosphate isomerase, G6pd -glucose-6-phosphate dehydrogenase, Idh -isocitrate dehydrogenase, Mdh -malate dehydrogenase, and Pgm -phosphoglucomutase) to determine genetic variability and levels of gene flow among Australian and South African populations. The two species could be distinguished by the most common allele at Gpi and usually Pgm. There was no evidence for subdivision among the Australian populations of H. destructor, but the levels of substructuring among the South African populations of H. destructor and those of H. anthropus were high. The geographic origin of H. destructor is discussed; the evidence suggests that the original source of the Australian populations of H. destructor was from Cape Town, South Africa.

The present paper revises the Australian and South African species of Halotydeus Berlese. The redlegged earth mite H. destructor (Tucker) is redescribed, and four new species are described (H. anthropus, H. bakerae, H. castellus and H. spedatus). A key to species is provided. Halotydeus destructor is an important pest of leguminous pasture and other crop plants, but the three Australian species (H. bakerae, H. castellus and H. spectatus) occur in native vegetation and are not believed to be of any economic significance. The pest status of the South African species H. anthropus has not yet been determined.

A new family of eupodine Prostigmata, Eriorhynchidae fam.n., is established to accommodate Eriorhynchus gen.n., and five species from Australia: E.australicus (Womersley), E.hades sp.n., E.ramosus sp.n., E.walteri sp.n. and E.womersleyi sp.n. The new family is unique in the possession of 15–34 setae on the gnathosomatic base, a naso‐prodorsal process with 9–28 setae and a palp tibia with 6 or 7 setae. A key to the families of Eupodoidea is provided. A cladistic analysis of twenty‐seven eupodoid species from Australia and New Zealand is presented. Results indicate that the genus Eriorhynchus gen.n. (thus Eriorhynchidae) is monophyletic, and the Australian and New Zealand species of Halotydeus Berlese, Penthaleus C. L. Koch, Rhagidia Thorell and Stereotydeus Berlese form separate monophyletic goups, while the Penthaleidae are not monophyletic. The new family Eriorhynchidae is a sister group to a clade consisting of Penthaleus and Chromotydaeus quartus Qin & Halliday.