Observations on the genus Pterygosoma (Acari: Pterygosomidae)

A generic diagnosis is given together with notes on infraspecific variation of known species in the subgenera Pterygosoma Peters, 1849, and Gerrhosaurobia Lawrence, 1958, and first descriptions of the following hitherto unrecorded stages. Males of P. transvaalensis, P. triangulare, P. hirsti hirsti, P. melanum melanum, P. melanum longipalpe, P. agamae aculeatum and P. persicum; nymphae of P. transvaalense, P. neumanni, P. agamae agamae and P. persicum; larvae of P. neumanni and P. agamae agamae. The following species are here considered to be subspecies: P. hirsti bedfordi Lawrence, 1936, P. melanum longipalpe Lawrence, 1936, P. agamae aculeatum Lawrence, 1936. The following species are reduced to synonymy: P. neumanni hirstielli Abdussalam, 1941 (= P. neumanni Berlese, 1910), P. rubicundum Lawrence, 1958 (= P. agamae agamae Peters, 1849). Three subspecies and two species are described for the first time, namely, P. fimbriata problematica, P. melanum angolae, P. melanum capensis, P. benguellae and P. spinosa. A list of parasitized lizard species with their scale-mite parasites is presented together with unparasitized lizard species of the Gerrhosauridae and the agamid genera Calotes and Agama. Support is given to Lawrence's (1936) conclusions on the factors preventing parasitization of the lizards. This is followed by a brief discussion of host-parasite relations and similarities between different species are evinced. Sincere thanks are tendered to Dr A. J. Hesse, Chief Entomologist, South African Museum, for the loan of paratype material of many species; to Dr R. F. Lawrence for making available slides of P. fimbriata, P. (G.) gerrhosauri and co-types of P. rubicundum; to Dr G. O. Evans, British Museum (Nat. Hist.), for advice and for the loan of Hirst's material of P. agamae, P. persicum, P. neumanni and P. inermis; to Mr J. C. Battersby and Miss Alice Grandison of the Reptile Section of the British Museum (Nat. Hist.) for facilitating the collection of parasites from the lizards under their care; and finally to Mr T. E. Hughes and Dr F. A. Turk for their invaluable advice and encouragement.