Population Genomics and Patterns of Host Use in the Cotton Fleahopper, Pseudatomoscelis seriatus (Reuter, 1876) (Hemiptera: Miridae)

The cotton fleahopper (CFH), Pseudatomoscelis seriatus (Reuter, 1876) (Hemiptera: Miridae), is a pest of commercial cotton (Gossypium hirsutum L.), with over 100 known host plants across its range. All life stages of the CFH attack cotton squares, leading to abscission of the squares. A new transgenic cotton cultivar has been developed that shows some resilience to CFH damage. However, due to the host plant associations found in some populations of this species, a genetically differentiated host-race may exist which is associated with cultivated cotton. If the CFH genotypes associated with cotton do not share gene flow with genotypes associated with other host plants, then this species could quickly develop resistance to the transgenic control. As cotton is only available as a host during part of the year, populations found on cotton must both shift from alternative hosts onto cotton at the beginning of the growing season, and back to alternative hosts at the end of the growing season. However, whether these host shifts are associated with gene flow between cotton-associated populations and populations associated with other host plants is unknown. Woolly croton (Croton capitatus Michx.) is an important overwintering host plant that is hypothesized to be a year-end site of admixture between populations coming from different host plants. We used a high-throughput sequencing (HTS) approach to resolve the population genomic structure of the CFH in the Brazos Valley, testing for gene flow between cotton populations and croton populations. Our preliminary results indicated that there is high gene flow between populations feeding on cotton and those feeding on croton and provided limited support for woolly croton as a natural refuge for the purposes of insect resistance management. Here, we present additional research including alternative host plants in order to better resolve the spatio-temporal dynamics of population genomics structure in this species.