Population dynamics and resource utilization of Rhyzopertha dominica in Manhattan, KS

The lesser grain borer (LGB), Rhyzopertha dominica (F.) (Coleoptera; Bostrichidae), is a primary insect pest of stored commodities such as wheat, sorghum, corn, and rice. LGB bores into whole, undamaged grain, making infestations difficult to detect, especially in early stages. Though LGBs are stored product pests, they can be found in natural habitats, such as tallgrass prairies. The dispersal of LGB is facilitated by the movement of infested grain between storage structures and processing facilities; however, the detection of LGB in natural landscapes suggests that the insect may be able to disperse without human intervention. LGB is a strong flier, and laboratory assays showed that it can survive on food resources found in tallgrass prairies, such as woody plant material and acorns. To determine whether populations of LGB found in tallgrass prairies interact with surrounding grain storage facilities, we collected insects from three trapping locations in Manhattan, KS, including a large grain elevator, a local flour mill, and a native tallgrass prairie. We prepared DNA libraries from double-digested LGB genomic DNA using restriction enzymes for Illumina sequencing to study the changes in population structure at the three sites from 2017-2019. Additionally, we are performing DNA metabarcoding analysis with plant-specific PCR primers in conjunction with Illumina sequencing to determine what food resources that LGB uses in tallgrass prairies. Understanding the relationship among the LGB populations at local scales can help develop preventative strategies for managing LGB in the surrounding landscapes before economic losses occur.