Seasonal shifts in the gut microbiome of Halyomorpha halys

The gut microbiome plays an important role in insect evolution and ecology. Bacteria support the host nutrition and defense and therefore play an important role for the fitness of the host. Halyomorpha halys is one of the most important invasive pest species in the world. Native to North-Eastern Asia, this Pentatomid bug has recently invaded North America and Europe, causing significant damage to agricultural production. Although an increasing number of studies investigated the biology of this pest species, little is known about its associated microorganisms. Like many other Pentatomid species, H. halys harbors a primary symbiont called ‘Candidatus Pantoea carbekii’, that produces vitamins and essential amino acids for the host. However, information about the presence of other bacteria is currently lacking. Therefore, we investigated the gut microbiome of H. halys individuals, which were collected in the field across the year using a high-throughput 16S rRNA gene metabarcoding approach. Our results revealed 645 different ASVs associated with H. halys, with Pantoea being the most abundant symbiont, present in almost all individuals. Interestingly, several individuals collected in summer harbor Commensalibacter. Besides these two predominant taxa, we show a high diversity of microorganisms associated with H. halys with seasonal fluctuations, highlighting a dynamic microbiome which might influence the biology of the species.