Using transcriptomics to target key behaviors of pear psylla (Cacopsylla pyri)

Pear psylla (Cacopsylla pyricola) occurs as two seasonal morphotypes - summerform and winterform - that differ in behaviors and biological traits including diapause, plant attraction, susceptibility to insecticides, and association with bacterial endosymbionts and plant pathogens. Initial results demonstrate variable gene expression among summerform, diapausing winterform, and post-diapause winterform pear psylla, and results are consistent with observed differences among the populations in behavior and biology. The top 50 highest expressed genes from each population were identified and compared to sequences deposited in the NCBI database. Genes were then categorized based on their putative function (immunity, muscle, photoreception, vitellogenin, or other biological processes) and origin (ribosome, mitochondria, Arsenophonus or Carsonella), or were designated as unknown. Although changes in behaviors and phenotypes associated with summerform, diapausing winterform, and post-diapause winterform psylla are well-documented, the timing for these behavioral changes and mechanisms controlling behaviors are not currently understood. The results of our studies will allow us to pinpoint the exact timing for these changes and will contribute to our long-term goal of providing a better understanding of winterform biology and improve management of this bottlenecked population.