D3425: Gut microbiome composition of grape berry moth (Paralobesia viteana) larvae

Grape berry moth (GBM) Paralobesia vietana, is an important pest of cultivated grapes in eastern North America. The larvae of this insect damage grape clusters by direct feeding and by increasing susceptibility to fungal and bacterial pathogens. In this study, we performed sequencing of V3-V4 region of 16S rDNA and V4 region of 18S rDNA to compare the composition and diversity of GBM gut bacteria, fungi, and yeast communities between larvae feeding on immature and mature Concord grapes. The results of 16S rDNA metagenomic analysis showed that Proteobacteria (96.2%) was predominant in all samples, followed by Firmicutes (1.9%) and Bacteroidetes (1.11%). The highest diversity of gut bacterial community was found in larvae fed on mature grapes. The 18S rDNA sequencing analysis showed that Ascomycota was predominant in all samples (78.5%), followed by Cryptomycota (34.2%), which was only present in larvae fed on immature grapes. Larvae fed on mature grapes had the highest diversity of gut fungal and yeast-like microorganisms. These results indicate substantial differences of GBM gut-associated microorganisms when fed on grapes at two different ripping stages. Our results may help elucidate interactions between GBM feeding and disease development in mature grapes.