D3014: Capacity of the larger grain borer and the maize weevil to vector microbes after foraging at novel food patches

There has been no work assessing the ability of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), to vector microbes after harvest. While there has been some work assessing the microbial ecology of the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Cucurlionidae), none has directly assessed whether they vector microbes. However, this has important ramifications for the safety of the post-harvest agricultural supply chain. Thus, we evaluated the ability of both P. truncatus and S. zeamais to vector microbes when given the opportunity to forage on potato dextrose agar dishes for 3 and 5 days. We subsequently photographed the dishes and quantified the microbial growth using ImageJ. In addition, we isolated unique morphotypes of fungi, and extracted DNA using a Zymo kit, amplified the DNA using PCR, and sent samples for sequencing to determine fungal identity. We found that both species readily vectored several plant pathogenic microbes, including Aspergillus niger, Aspergillus flavus, and Fusarium spp. Microbial growth was greater at 5 days compared to 3 days. These results have important implications for food safety in the postharvest environment, especially for maize production.