Host Relations and Distribution of Australian Species of Charletonia (Acarina, Erythraeidae) Parasitizing Grasshoppers

Abstract

The geographical distribution and host relations of the 12 species of Charletonia whose larvae are known to parasitise 'short-horned' grasshoppers (Orthoptera) in Australia are described. The eight species for which there are adequate records occupy territories in the form of mainly overlapping bands running approximately from north-west to south-east and succeeding each other in a south-west to north-east direction across the continent, in correlation with isopleths of mean monthly effective moisture for the summer months. As many as 107 species of grasshoppers are attacked, encompassing all four of the Australian subfamilies of Acrididae, the Morabinae (Eumastacidae), and occasionally the Pyrgomorphidae. There is little evidence of host specificity and none of sexual preference. Sites of attachment on the host vary with the species of mite, from predominantly the prosternum to predominantly the alar organs, or, less frequently, various. Most of the host individuals were attacked by only one mite.