Ecology of Ecto-parasites of Some Cave-dwelling Microchiropterans of Sri Lanka

Abstract

The population and community characteristics of ecto-parasites of bats in Sri Lanka have not been previously examined. The aim of the present study was to investigate these attributes based on incidence, density, prevalence and species composition of ecto-parasites harboured by 3 species of cave-dwelling microchiropteran hosts, Hipposideros lankadiva, H. speoris and Rhinolophus rouxi. These bats were captured by hand or mist nets at four previously selected sites, distributed in the wet, dry and intermediate zones of Sri Lanka. Parasites were both hand-picked and brushed off the pelage from slightly anaesthetised bats. Five species of bat flies including 2 nycteribiid flies (Phthiridium ceylonicum and P. phillipsi ), 3 streblid bat flies, Brachytarsina modesta, B. pygialis and Raymondia pagoda rum and mites offamilies laelapidae, spintumicidae and trombiculidae were recorded on these hosts. With the exception of the two streblid flies and individuals of the three mite families, the other ecto-parasites were host specific. The highest incidence and density were recorded for laelapid and spintumicid mites on H. lankadiva, while lowest values for these indices were also for the same mites on R. rouxi in the intermediate zone. No significant difference (2-way ANOV A; P> 0.05) in the prevalence of ecto-parasites could be attributed either to the sex or the climatic zone of the host with respect to R. rouxi and H. speoris. The ecto-parasite species diversity on H. speoris in the dry zone was observed to be the highest and that on H. lankadiva in the wet zone the lowest. A significant difference in the ecto-parasite assemblage of all hosts were observed except between the populations on H. lankadiva and H. speoris occurring sympatrically in the wet zone. It is concluded that the prevalence of cere-parasites is neither dependant on the gender of the host nor the climatic zones oftheir roosting sites.