By Seun Oladipupo, Ph.D
Insects are fascinating! Yet, insects can also be a source of nuisance. For example, cockroach infestations in homes can be a source of allergen triggers, mechanical vectors of pathogens, and embarrassment to homeowners as cockroaches often move from filth to food in homes and are perceived as a sign of poor hygiene/sanitation. Cockroach management often relies heavily on the use of insecticides and sprays, which, due to evolving resistance among some cockroach populations, no longer provide the anticipated level of control. However, there may be a new avenue for cockroach control using knowledge of cockroach endosymbionts like Wolbachia.
Wolbachia is a type of bacteria found living within many insects. The bacterium is passed from a mother to its offspring. To ensure this, Wolbachia manipulates the reproductive biology of its insect host. For example, Wolbachia can kill all the males in an insect population. Wolbachia can modify sperm making it toxic to eggs. Wolbachia can turn biological males into females. Also, Wolbachia can promote host dependence by providing essential nutrients.
The type of Wolbachia-mediated reproductive manipulation, however, depends on the strain found in an insect. In a new study published in May in the Journal of Economic Entomology, my colleagues at Auburn University and Aix Marseille Université and I explored the possibility of Wolbachia as a potential tool to control cockroaches. We screened 16 cockroach species across three families—Ectobiidae, Blattidae, and Blaberidae—for the presence of Wolbachia. The goals were to (1) uncover the frequency of Wolbachia in intractable cockroach species like the German cockroach (Blattella germanica), (2) determine the Wolbachia strain in the Wolbachia-infected cockroaches, and (3) predict the type of Wolbachia-mediated reproductive manipulation. Taken together, such knowledge could give insights that could be exploited for effective cockroach control.