Evaluation of different irradiation doses for Aedes aegypti (Linnaeus) to optimize the Sterile Insect technique for arbovirus control in Burkina Faso (West Africa).

The sterile insect technique (SIT) relies on the release of sterile males that mate with wild females, thereby reducing the reproductive capacity of the target population. Its effectiveness depends on identifying an irradiation dose that induces high sterility while preserving male biological quality. This study evaluated the effects of gamma irradiation doses of 20, 30, 50, 70, and 90 Gy on adult emergence, flight ability, survival, fecundity, and fertility in a laboratory strain of Aedes aegypti established from a population collected in Burkina Faso. The results show that irradiation did not significantly affect adult emergence, which remained at or above 95% across all doses. Flight ability was also maintained at doses of 20 - 70 Gy, whereas only 61% of adults irradiated at 90 Gy successfully exited the flight-test device, compared with 92% in the non-irradiated control group. Male survival was significantly reduced at 50, 70, and 90 Gy relative to the control group. No eggs hatched at 70 or 90 Gy, indicating complete sterility under the experimental conditions. Among the doses tested, 70 Gy provided the most favorable balance between induced sterility and preservation of adult emergence and flight ability, although it significantly reduced male survival. These results therefore show that a dose of 70 Gy would be optimal for implementing SIT against Aedes aegypti in Burkina Faso. Additional studies should assess the mating competitiveness and field performance of irradiated males under semi-field and field conditions.