Mites Associated With British Species of Ornithomya (Diptera: Hippoboscidae)

The ♀♀ of Strelkoviacarus quadratus (Haller), S. critesi Spory, Microlichus avus (Trouessart), Mi. uncus Vitzthum, Myialges macdonaldi Evans et al. and My. anchora Sergent & Trouessart are redescribed, illustrated and keyed. The first five species were collected at Gibraltar Point and Fair Isle Bird Observatories, Britain, from Ornithomya flies taken from birds. My. anchora is included on the basis of records in the literature. Only adult ♀♀ mites were collected from flies. Different birds, and sometimes different flies, were preferred as hosts by the various mites. The mites were topographically separated on the flies. Some were invariably accompanied by eggs, while others were not. Also, there were definite seasonal variations in abundance which generally correlated with the seasonal occurrence of the flies on the hosts. All of the mites are assumed to be primarily skin or feather parasites of birds. In some cases adult ♀♀ are phoretic on the flies whereas in others they are hyperparasitic. The association of mites-flies-birds is the chief means of dispersal of mites from bird to bird.