Survey of the nasal mite fauna (Rhinonyssidae and Kytoditidae) of the Gouldian finch, Erythrura gouldiae, and some co-occurring birds in the Northern Territory

The rhinonyssid and kytoditid mite fauna in the Gouldian finch and six co-occurring species in the Northern Territory were surveyed over a 3-year period to assess prevalence and intensity of infection and to determine the stability in these parameters over space and time. These data were used to examine the likelihood that prevalence and intensity of infection by the rhinonyssid mite Sternostoma tracheacolum in the endangered Gouldian finch, Erythrura gouldiae, are in any way aberrant. Twelve new host records for rhinonyssid and kytoditid mites are reported from two localities in the Northern Territory. Kytonyssus andrei is a new genus record and Sternostoma paddae and Kytodites amandavae are new species records for Australia, Sternostoma tracheacolum was found to infect the Gouldian finch, pictorella mannikin, Heteromunia pectoralis, masked finch, Poephila personata, and budgerigar, Melopsittacus undulatus. Prevalence and intensity of infection were significantly higher in the Gouldian finch than in the masked finch and budgerigar, but were not significantly higher than those found in the pictorella mannikin. The frequency distribution of infrapopulation sizes of S. tracheacolum in pooled Gouldian finch samples was significantly different from that found in pooled budgerigar and masked finch samples but not from pooled pictorella mannikin samples. Prevalence and intensity of infection by rhinonyssid mites in the Gouldian finch were significantly higher than infection in all other host species examined, except the pictorella mannikin. Significant increases in the intensity of infection in the pictorella mannikin were detected between 1992 and 1994, suggesting that this species may also be under threat from parasitism by S. tracheacolum.