Development of SNP-Based Diagnostic Tools for Boll Weevil Variant Identification

The southeastern boll weevil (Anthonomus grandis grandis Boheman) remains a persistent concern for cotton growers in the Lower Rio Grande Valley of Texas, and re-infestations of cotton growing regions in previously eradicated areas highlight the broader threat of boll weevil range expansions to other parts of the Cotton Belt. Additionally, recent research suggests that the Thurberia weevil (Anthonomus grandis thurberiae Pierce) in the southwestern United States, previously thought to be a wild host-associated variant of the species, may actually represent a geographically differentiated lineage that can equally pose a threat to commercial cotton. An important component of area-wide control measures for the boll weevil is to limit reintroductions to successfully eradicated areas from areas that remain infested. Thus, it is critical that managers and governing agencies can rapidly and accurately identify source populations for re-infestations so that control strategies can be more precisely targeted. Here, we present progress on the development of a rapidly deployable SNP-based qPCR assay using TaqMan fluorescent probes. Using a variety of samples from different geographic areas where boll weevils regularly occur, samples from recent outbreaks, and samples with varying degrees of genomic DNA quality, we demonstrate the promise of the best-performing assays and contrast these results with existing methods of source identification.