SRA

Microbial profiling of the solitary bee nest environment is a challenging task due to the multiple aspects of the solitary bee ecology. Solitary bees build their nests by modifying the interior of natural cavities using various environmental materials and they provision them with food by importing collected pollen. As a result, the microbiota of the solitary bee nests depends on a variety of introduced materials. In order to characterize the extent to which introduced pollen affects the nest microbiome, we used metabarcoding of the ITS2 rDNA and the 16S rDNA to characterize the pollen composition and the bacterial communities of 100 solitary bee nest chambers belonging to seven megachilid species. Although the identity of each bee host species was the main driver of variance for the nest bacterial communities, pollen composition also had an effect on their structure. We found a weak correlation between bacterial and pollen alpha-diversity and significant interactions between the composition of pollen and that of the nest microbiota. This study contributes to the understanding of the association between foraging preferences and bacteria acquisition for solitary bees which cannot establish bacterial transmission routes through eusociality. This association may be essential for the successful offspring recruitment for this group of valuable pollinators.