Rabbit Burrows as Environments for European Rabbit Fleas, Spilopsyllus-Cuniculi (Dale), in Arid South-Australia

Abstract

The temperature and humidity of air within rabbit burrows was recorded for sites on either side of the margin of the distribution of the rabbit flea, Spilopsyllus cuniculi, in South Australia. The microclimate in the burrows differed significantly across this margin, and the differences in temperatures and humidities were large enough to have significant effects on flea populations. At sites where fleas occurred, the relative humidity of burrow air was above 70% and usually between 80 and 90% RH for at least 4-5 months during the winter and spring. This not only provided optimum conditions for the survival of flea larvae in the rabbits' nests, but also should have enabled the flea populations to achieve their full reproductive potential. High humidity of burrow air at these sites during summer would also favour the survival of free-living adult fleas. At those sites where fleas did not occur, the humidity of burrow air is generally unsuitable for the survival of larvae or free-living adult fleas.