Persistence of diet effects on the microbiota of Drosophila suzukii (Diptera: Drosophilidae)

Abstract

AbstractThe insect commensal microbiota consists of prokaryotes and eukaryotes. We explored the effect of diet and the persistence of the gut microbiota across generations in Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). We transferred subsets of a single population of D. suzukii to different fruit-based diets (blueberry (Vaccinium Linnaeus; Ericaceae), raspberry (Rubus Linnaeus; Rosaceae), and strawberry (Fragaria × ananassa Duchesne; Rosaceae)) for three generations and then returned them to a common, banana-based, diet. We used 16S rDNA (Bacteria) and ITS (internal transcribed spacer; Fungi) sequencing of female endosymbiont-free flies to identify the microbiota. We identified 2700 bacterial and 350 fungal operational taxonomic units (OTUs); there was no correlation between the number of bacterial and fungal OTUs in a sample. Bacterial communities were dominated by Proteobacteria (especially Acetobacteraceae); Ascomycota dominated the fungal communities. Species diversity of both bacteria and fungi differed among diets, but there were no differences in species-level diversity when these D. suzukii were returned to a control diet. A principle coordinates analysis revealed no differences in the bacterial or fungal community in the first generation on fruit diets, but that the communities diverged over the next two generations; neither fungal and bacterial communities converged after one generation on control food. We conclude that diet changes the D. suzukii microbiota, and that these changes persist for more than one generation.