D3341: Does the source matter for SIT? No effects of x-ray vs gamma irradiation on sterilization or sterile male performance in the mosquito Aedes aegypti

Sterile insect technique (SIT) can be effective as a component in area-wide integrative pest management for multiple insect pests. SIT may be particularly useful for vector mosquitoes like Aedes aegypti that live in close proximity to humans, occupy cryptic larval breeding sites with adults resting in places difficult to reach with insecticide sprays, and that have populations showing resistance to common chemicals. For SIT, males are typically sterilized by exposing them to gamma radiation. However, gamma irradiators are not always available of easily accessible due to restrictions on the radio-isotopes used. One solution to this problem is to irradiate male mosquitoes using x-rays rather than gamma sources because x-ray irradiators are readily available, relatively affordable, and do not require the stringent safety and security restrictions necessary for gamma irradiators. Here we compare an established gamma irradiator heavily used for an operational Ae. aegypti SIT pilot program with that of a new x-ray irradiator for sterilizing male pupae and adults while maintaining male performance after irradiation. Our results show Aedes aegypti SIT programs can successfully transition from gamma to x-ray sources, and new programs can begin using x-ray irradiation sources to avoid regulatory and cost hurdles associated with gamma sources.