Wolbachia are maternally transmitted bacteria that are present in approximately 25% of all insects. Their spread is accomplished by various means of manipulating host reproduction, including asexual parthenogenesis and killing embryonic males. The spread of these infections is governed by the fidelity of maternal transmission and the effectiveness with which Wolbachia manipulates host reproduction. The proposed research will examine how environmental variables, including season, temperature, mushroom antibiotics, and fly age, affect the density of a male-killing Wolbachia within its host species, Drosophila innubila. The research will also quantify variation in Wolbachia density among flies in the wild and experimentally determine the relation between Wolbachia density and offspring sex ratio.
Wolbachia occur in some insects (such as mosquitoes and tsetse flies) that are vectors of important human diseases, and they related to bacteria (such as Rickettsia, Anaplasma, and Ehrlichia) that are pathogenic to humans and domesticated animals. The proposed research will contribute to understanding the dynamics of these infections in natural populations, about which very little is known. The novel component of this research is that it will connect the population dynamics of these infections at two levels: density variation within individual hosts and percent infection in populations of these hosts. The research may also lead to the discovery of new antibiotics.
