Transport from production facility to release locations caused a decline in quality of sterile Queensland fruit fly received for SIT application

Abstract

AbstractFruit flies are among the most destructive horticultural pests. For Queensland fruit fly (Qfly), Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), the sterile insect technique (SIT) is the main control method used in southeastern Australia. SIT involves the mass rearing of Qfly, sterilisation of pupae by irradiation, transport to release centres, and release of sterile Qfly to disperse into the environment. Mating of sterile and wild flies results in no offspring; thus, the wild population rapidly decreases. Previously, research has mainly focused on improvements within the production facility. However, transport from production facility to release sites is also an essential component in all SIT programs. Here, we examined historical records from the Victorian SIT program between 2002 and 2013 in three seasons (spring, summer, and autumn). We compared quality control (QC) data of irradiated fly pupae at the mass‐rearing facility in New South Wales (limited transport) to those of pupae transported to a release centre in Victoria (extensive transport). After extensive transport, pupal weight (−0.3 mg, or −3%) and flight ability (an overall 26% decline) were lower across all seasons, but particularly in spring. Adult emergence was lower across all seasons (an overall 23% decline), but particularly in summer. All three QC parameters were more variable after extensive transport. We discuss potential causes of the observed decreased pupal quality and avenues of future research to mitigate transport losses.