Trombiculid Mites (Chiggers) and Other Ectoparasites as Vectors of Rickettsial Infections.

A new species of Leptotrombidium Leptotrombidium, collected in the mountains of Ethiopia, constitutes the first record of a member of the subgenus in Africa. This species is related to the vectors of chigger-borne rickettsiosis. Since the infection has been found wherever such species occur when sought, search for endemicity in Africa seems warranted, especially since there have been uninterpretable serological reports of cases of scrub typhus on the continent. New data have been obtained to support the authors theory that the Leptotrombidium deliense complex of chiggers are fundamentally parasites of Rattus in secondary vegetation, and not of the more primitive murines in primary jungle. The only records of L. deliense and an allied species in New Guinea are from grass or the forest edge, while in the undisturbed forest there is another fauna, characteristic thereof. The chigger fauna of New Guinea is not nearly as well known as had been believed. Eleven of the 21 species encountered in the above survey are new to science 5 of the 7 species collected thus far in Ethiopia are new species. Field studies on murine typhus in Ethiopia have provided excellent background material for new investigations. It is now known where to collect in numbers the various species of fleas intended for colonization endemic foci for various studies have been pinpointed.