2025/01/01 by Kevin D. Floate, Paul C. Coghlin, Robert A. Laird · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Entomopathogenic Microorganisms in Pest Control #Insect and Arachnid Ecology and Behavior #Insect symbiosis and bacterial influences
paper · doi:10.1139/cjz-2025-0040
openalex publication_date 2025/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Wolbachia are obligate intracellular bacteria common in diverse arthropod hosts. Infections are spread from infected mothers to their progeny via egg cytoplasm. Establishment and spread of infections are affected by the number of infected individuals invading the novel host population plus the effect of infections on the production of female progeny and mating behaviour. Here, we examined the ability of Wolbachia to establish and spread in populations of the parasitoid wasp Trichomalopsis sarcophagae (Gahan, 1914) (Hymenoptera: Pteromalidae). Uninfected females mated with infected males only produced male progeny and broods of smaller size, which was attributed to fertilized eggs developing as though male or failing to develop. All other mate combinations produced normal broods of similar size and sex ratio. Mate-choice tests showed that females mated once and showed no preference for infected or uninfected males. An experiment tracking the extinction or subsequent establishment and spread of Wolbachia infections in laboratory colonies for 20+ generations indicated an establishment threshold for infection prevalence of less than 10%. The existence of such a threshold, and its relatively low value, is broadly consistent with a simple mathematical model informed by the results from the experimental crosses and mate-choice tests. This is one of few experimental studies tracking the spread of Wolbachia infection in an insect species. It helps explain why Wolbachia is such a successful and widespread parasite.