Location: Commodity Protection and Quality Research
Project Number: 2034-43000-043-042-R
Project Type: Reimbursable Cooperative Agreement
Start Date: May 12, 2021
End Date: Dec 31, 2024
Objective:
Verify and optimize x-ray sterilization of navel orangeworm and codling moth (Objective 1 in the main proposal) and evaluate inherited sterility in navel orangeworm and codling moth following x-ray irradiation (Objective 3 in the main proposal).
Approach:
Optimize x-ray sterilization: Following irradiation groups of five irradiated and non-irradiated (control) males and females of each species will be paired with non-irradiated virgin counterparts in mating-oviposition jars. Moths will be allowed to mate and oviposit for a period of 5 to 7 days, after which oviposition papers will be removed and placed in petri dishes of 6 cm diameter. Dead moths will be removed from mating jars and placed in 4-ml vials with a 50% ethanol–water solution. To determine mating status or success, the bursa copulatrix of female moths will be dissected and absence or number of spermatophores noted. The petri dishes of eggs laid for all irradiation treatments and controls will be observed for a period of 6–21'days post-treatment to determine the fecundity (number of eggs laid), fertility (number of eggs hatched) and eclosion of F1 progeny. The data from irradiated moths should be compared to unirradiated control pairs.
Determine sub-sterilizing x-ray dose for navel orangeworm and codling moth: As a preliminary step, this phenomenon of inherited sterility will be investigated by outcrossing (1) the offspring of navel orangeworm adults (F1) treated with a sub-sterilizing x-ray dose with (2) nonirradiated males and females. Initial sub-sterilizing dosages will be determined based on findings from Objective 1, and fertility of F1 offspring will be assessed in the same way as described in Objective 1. F1 sterility for codling moth has been developed by the British Columbia Sterile Insect Release program using Cesium gamma radiation, but it is not known if these dosages will transfer to radiation under eBeam or X-ray. Therefore, mirrored studies will be conducted for codling moth.
