An Integrative Approach to Finding the Genetic Basis of a Genetic Sexing Trait Textitwhite Pupae in Bactrocera Cucurbitae

The melon fly Bactrocera cucurbitae (Coquillette), is a destructive agricultural pest and is among one of the many species that is the target of expensive population eradication and suppression efforts within state and federal departments of agriculture. Area-wide integrated pest management programs control some species such as the Mediterranean fruit fly and the Mexican fruit fly through the release of sterile males known as the sterile insect technique (SIT). This method is not currently employed for B. cucurbitae in the United States though a genetic sexing strain (GSS) with a sexually dimorphic pupal color morph that can be used for mass-rearing and release does exist for the melon fly. The purpose of this project was to identify the causative gene and mutation of the genetic sexing trait white pupae (wp) in the genetic sexing strain of B. cucurbitae. To do so, we combine QTL mapping, 3’ mRNA sequencing, and low-coverage whole genome re-sequencing to investigate the possible causative mutation for white pupae and genes that are involved in the pupal color process. These methods combined allowed for extensive sampling and replicates to improve statistical power at a substantial reduction in cost. Ultimately, this study results in the identification of the gene conferring the genetic sexing trait white pupae can be used to develop novel genetic sexing strains for use in SIT of other economically important agricultural pests.