Primary and Secondary Symbionts of Cambodian Cicadellidae and the Role of Parasitisation

Leafhoppers (Hemiptera: Cicadellidae) are important vectors of plant pathogens in agricultural systems. Biological control via parasitisation is a key management strategy, but little is known about how microbial symbionts mediate host-parasitoid interactions. Here, we characterise the bacterial communities of six Cambodian leafhopper species (Cofana spectra, Exitianus sp., Goniagnathus punctifer, Maiestas dorsalis, Nephotettix virescens, and Stirellus sp.) and their parasitoids from the families Dryinidae (Hymenoptera) and Halictophagidae (Strepsiptera). We found that the bacterial symbiont Sulcia dominates cicadellid microbiotas, often coexisting with secondary symbionts. For example, Nasuia is present alongside Sulcia in Nephotettix, while Wolbachia is prevalent in Exitianus and Goniagnathus. Parasitoids exhibited distinct microbiotas with greater diversity; Rhodobacteraceae and Comamonadaceae were in dryinids, while Wolbachia was common in Halictophagidae. We analysed the microbiota of individual pairs of host-parasitoid and although parasitism did not significantly alter cicadellid overall microbiotas, some secondary symbionts (e.g., Arsenophonus, Wolbachia, Rickettsia, and Sodalis) were detected in both hosts and parasitoids, suggesting possible microbial transmission that warrants further investigation. These findings improve our understanding of host-parasitoid microbial interactions and highlight the relationship between primary and secondary symbiont communities.