Breeding of the Rabbit Flea (Spilopsyllus cuniculi (Dale)) controlled by the Reproductive Hormones of the Host

Abstract

THE rabbit flea (S. cuniculi) is a host-specific parasite of the rabbit. Before the outbreak of myxomatosis in Britain all populations of rabbits examined from the mainland were infested and the flea index was high^1,2. The first hint that the breeding cycle of the flea was linked to the hormone cycle of the host came from Allan's¹ observation that shortly before the breeding season commenced, female rabbits carried an extra load of fleas. Further observation enhanced this view, and Rothschild^2,3 suggested that the breeding cycle, especially copulation, was under the influence of the sex hormones of the host. This suggestion was followed up by Mead-Briggs⁴, who proved that: (a) maturation of the ovaries of female rabbit fleas could only take place on a pregnant female rabbit; (b) that immediately after parturition the fleas from the does were to be found in the nest containing the young rabbits, where they fed on the young and laid eggs.