Host Relations and Distribution of Species of Caeculisoma (Acarina, Erythraeidae) Parasitizing Grasshoppers in Australia, With Supplementary Information for the Genus Trombella (Trombellidae)

Abstract

The geographical distribution and host relations of the two species of Caeculisoma whose larvae are known to parasitise adult grasshoppers (Caelifera) in Australia are described. Most of the data refer to C. darwiniense, with 207 specimens taken at 97 localities on 140 individual hosts belonging to 57 species. Its distribution probably extends over all but the south-eastern and south-western corners of mainland Australia. C. cooremani was recorded only from the central western coast of Western Australia. Only Acrididae of the subfamilies Catantopinae, Cyrtacanthacridinae, and Acridinae appear to be attacked. In C. darwiniense there is little evidence of discrimination in parasitisation of different host species or between the sexes. Most host individuals are parasitised by only a single mite. Some 80% of the mites were attached to the tegmen or wing, especially the latter. In this respect C. darwiniense differs radically from Trornbella cucumifera.