The sheep scab mite, Psoroptes ovis, is the causative agent of a disease with
significant economical implications and causes severe disease which can be life-threatening if untreated. Research into this ectoparasite is restricted by the expense and practical difficulties entailed with artificially infesting sheep- currently necessary due to the lack of a suitable animal model or an artificial system for culturing the mites off-host. This thesis is an investigation into many aspects of the mites' biology and ecology which were poorly understood but crucial for the development of an in vitro culture system.
Investigations into the mites' natural environment and the environmental conditions that produce optimum survival off-host are presented. The nature of the mites' diet was investigated initially by SDS-PAGE and Western blotting followed by light microscopy and immunohistological techniques. With this information several in vitro feeding devices were developed and some preliminary investigations into mite survival off-host on a variety of fluid diets were conducted. The structure and ultrastructure of the mites' digestive system was investigated and compared to other related acarines. These studies revealed that the mites' digestive system contained a significant population of bacteria which were isolated and cultured in a separate study. The potential importance of these bacteria is fully discussed.