Temperature as a critical factor in the mating behaviour of the rat flea,<i>Nosopsyllus fasciatus</i>(Bosc.)

Abstract

1. Both male and female N. fasciatus normally require a blood meal before they will mate. 2. Fed males do not attempt to mate with unfed females. It is suggested that the taking of a blood meal enables the female to provide a stimulus necessary for the male to show mating behaviour. 3. Unfed Nosopsyllus of both sexes will mate if subjected to a temperature between 30 and 35°C inclusive. Above 35° mating does not occur. 4. Below 30°C mating occurs only if the fleas have previously been subjected to a temperature of 30°C or above. A temperature rise to the critical point thus acts as a trigger for an enabling process which continues after temperature has again fallen. 5. It is suggested that the effect of a blood meal in enabling mating to occur may be explained by the fleas' experience, while on the host, of a rise in temperature to the level critical for mating.