Microbiome composition of adult western corn rootworm (Diabrotica virgifera virgifera) and northern corn rootworm (Diabrotica barberi)

In the United States, two rootworm species predominate east of the Rocky Mountains: the western corn rootworm (D. virgifera virgifera LeConte; WCR) and the northern corn rootworm (D. barberi Smith & Lawrence; NCR). They comprise the most damaging groups of corn pests in the United States, with management costs and yield losses combining for over $2 billion annually. Both species overlap in distribution, phenology, and host plant usage, which provides a useful system to investigate the impact of host species identity and local environment on microbiome composition in insects. We sampled adult beetles of both species from corn fields across the United States. The main objectives were to describe adult beetle microbiomes for both species and determine how the location the insect was collected from impacts the microbiome. We sequenced the hypervariable region of 16S rRNA bacterial gene and compared bacterial communities between insects and locations. Increased understanding of the factors influencing microbiome composition in insects can provide insight into how microbe-mediated effects on plant-insect interactions may have evolved.