Ectoparasites of Mammals

Abstract

ITHE wingless permanent ectoparasites of mammals are chiefly of two groups, namely, the Mallophaga, or biting lice, which feed on the hair and dermal scales, and the Anoplura, or sucking lice, which feed on the blood.Certain mites and ticks, a few of the Pupipara (degenerate flies) and almost all of the fleas are also ectoparasites of the mammals, but the fleas, numerous and economically important as they may be, are not permanent parasites, for they live as larvae not on the host of the adult, but in cracks and crevices in floors, or in the soil and elsewhere that the organic detritus used by them as food may be found.The adults, too, hop on and off their host, and often change from one host individual to another, and even from one host species to another.So that the problems of distribution and species-forming with which I am particularly concerned in my studies of the ectoparasites are not at all the same in such impermanent form as the fleas as in those truly permanent forms, the Mallophaga and Anoplura.In these latter there occurs an extraordinary limitation of the parasite individuals and their immediate progeny and future generations to specific and even individual hosts (and their progeny and future generations), so that the Mallophagan and Anopluran fauna of any mammal usually represents a closely inbred family strain biologically iso-