A comparison of the structure and diversity of the microbial communities of Culicoides midges

Culicoides midges (Diptera: Ceratopogonidae) comprise over 1400 species globally and are vectors for several human and veterinary pathogens. The microbiota of insect vectors plays an essential role in the interactions between the host and pathogen and can impact the ability of the insect to transmit pathogens or parasites. Characterizing the microbiome composition of Culicoides could yield novel approaches to control midge populations and impact disease transmission. This study characterized and compared the bacterial and fungal microbiota of five Culicoides species. Utilizing 16S and ITS amplicon sequencing, we identified diverse bacterial communities, with Proteobacteria as the most abundant phylum. Notably, Rickettsia, Midichloria, and Asaia were the predominant genera across samples. Fungal analysis revealed Ascomycota as the primary taxon, with Cladosporium being the most prevalent genus. Little difference in overall bacterial and fungal diversity was observed between species, suggesting that the five Culicoides species examined share some common members of their microbiota but differ in overall composition. Our findings highlight the potential of exploiting midge-associated microbiota for developing novel biological control strategies to target Culicoides species populations and the pathogens they transmit.