Biological Technician Anastasia Mosquito Control District, Florida, United States
Abstract: This study aimed to determine the minimum effective radiation dose required to induce ≥99% sterility in a local St. Augustine strain of Aedes aegypti for use in a Sterile Insect Technique (SIT) program, while preserving male fitness and mating competitiveness. Male mosquitoes were irradiated at doses of 40, 45, 50, and 55 Gy. A sterility level of 99% was achieved at 47.1 ± 2.1 Gy. Based on this, 50 Gy was selected for mating competitiveness assays. Competitiveness was evaluated using virgin females at male ratios of 1:1, 5:1, and 10:1 (irradiated:non-irradiated). Results showed comparable mating performance between irradiated and non-irradiated males, with a Fried’s competitiveness index of C=1.12. No significant difference in induced sterility was observed between 5:1 and 10:1 ratios. Therefore, 50 Gy was identified as the optimal dose for operational SIT releases, maintaining both sterility and male fitness.
