Impact of male-sterilizing doses and mating status on blood feeding rates and longevity in Aedes aegypti, Aedes albopictus, and Anopheles arabiensis females

The irradiation of female mosquitoes has been shown to influence blood feeding behavior, depending on dose, life stage at irradiation, and mating status. In sterile male releases during the sterile insect technique (SIT) programs, a small number of sterile females can be released accidentally, which may pose a manageable but nonnegligible risk regarding disease transmission. In this study, female Aedes aegypti, Aedes albopictus, and Anopheles arabiensis were exposed to gamma irradiation at male-sterilizing doses and the blood feeding rates and longevity of mated versus unmated sterile females were assessed. Although some differences were observed between the three species, generally females irradiated at the pupal stage showed a marked decrease in blood feeding rates, while irradiated adults showed slightly higher feeding rates, more pronounced in the second week (for Aedes spp.). Overall, blood feeding females irradiated as pupae that were mated died soonest, while in the non-blood fed groups, irradiation only correlated with negative effects on survival in Ae. aegypti, and mating status correlated with diminished survival in Ae. albopictus. Although the overall risk of a small number of mated, irradiated females participating in disease transmission in SIT programs is expected to be very low, rigorous sex separation and quality control will minimize this risk, and developing genetic sexing strains to ensure safety should be prioritized.