Using a nuclear technique applied at a large scale against agricultural pests around the world to control disease-transmitting mosquitoes has been an elusive goal for scientists over the last decade. Thanks to a US$ 3.96 million grant to the IAEA by the U.S. Government, important milestones have been reached in recent years. The research has been implemented in cooperation with the Food and Agriculture Organization of the United Nations (FAO).
Optimizing the mass rearing of mosquitoes for sterile insect technique (SIT) applications and improving technologies to separate males from females, both being crucial for large-scale implementation of the technique, are key outcomes.
“The focus of this research was to develop the SIT package for disease-transmitting mosquitoes, with an emphasis on the Aedes mosquito which transmits the Zika virus, and to pass on this technology to the Member States,” said Rui Cardoso Pereira, Head of the Insect Pest Control Section at the FAO/IAEA Joint Division of Nuclear Techniques in Food and Agriculture. “Thanks to this grant, more advanced and cost-effective tools are now available for any country wishing to carry out pilot trials.”
More than half of the world’s population lives in areas where this mosquito species is present, according to the World Health Organization (WHO). In addition to the Zika virus, the Aedes mosquito also carries viruses that cause chikungunya, yellow fever and dengue fever, among others.
SIT is an environment-friendly insect pest control method involving the mass-rearing and sterilization, using radiation, of a target pest, followed by the systematic area-wide release of the sterile males by ground or by air over defined areas. Released males mate with wild females resulting in no offspring, which leads to a declining pest population.
One of the main challenges in SIT when it comes to mosquitoes is separating males from females in order to ensure that only sterilized males are released into the wild. Eliminating reared female mosquitoes is essential for safety reasons, as they, unlike males, can transmit viruses. It is also useful for SIT programme efficacy: Since the goal is for sterile males to mate with wild females, releasing sterile females introduces more competition for mating and may delay progress in suppressing a pest population.