Phylogeny and host specificity of Psoroptic mange mites (Acarina : psoroptidae) as indicated by TTS sequence data

We used molecular phylogenetic techniques to study the systematic relations hips and host specificity of Psoroptes mange mites, which are pests of nume rous domestic and wild ungulates. Phylogenetic analysis of DNA sequence dat a from the internal transcribed spacer region 1 (ITS1) of nuclear ribosomal DNA indicated that populations of Psoroptes are not host specific. Further more, the currently used taxonomy of Psoroptes is not concordant with the p hylogeny derived from ITS1. During the course of the study, we discovered a pparent paralogous ITS sequences within individual mites as a result of var ying polymerase chain reaction reaction conditions. This finding concords w ith other studies of ITS and suggests a cautious approach when interpreting data from ITS sequences. Host DNA contamination was also found to be a sig nificant problem in data collection, and we report on the development of me thods to overcome the problems of contamination in parasitic mites.