A drone equipped with sensors, cameras and an insect storage unit helped evenly disperse more than 200,000 sterile male mosquitoes across a rural area on the eastern tip of Brazil, a hotbed of vectors for diseases like malaria, dengue and Zika.
The strategy helped limit fertility in male mosquitoes and reduce viable eggs laid by female mosquitoes in the 20-hectare trial area, reports the study.
Developed in Brazil, this technology might offer substantial savings in operational costs as compared to other sterile insect release techniques; compared to a ground-based approach used in China, it offered more than a 20-fold reduction in total costs, as one example.
The sterile insect technique (SIT) is the original genetic control method and has been used with great success against insect pests, but aerial release approaches will be required to ensure cost-effective releases, especially when large areas need to be covered.
Currently, few automated systems exist for the efficient aerial release of sterile mosquitoes or other insects. Jérémy Bouyer and colleagues developed and tested a fully automated sterile mosquito system, whereby drones released sterile adult male Aedes aegypti mosquitoes across a rural village in Brazil.
Mosquito recapture analyses showed the aggregation of sterile males shifted the balance toward a higher sterile-to-wild male mosquito population over a large area.
Furthermore, analysis of female mosquito fertility using “egg traps” indicated the sterile males were able to induce sterility in the native female population; the proportion of unviable eggs collected in the release area increased by more than 50% as compared with that of a neighboring area where no mosquitoes were released.
In future work, the researchers hope to further slash the cost of their technology by chilling the mosquitoes and shipping them, abolishing the need for costly emergence and release centers in target areas.
“This new drone technique for sterile release is cheap enough to allow a reduction in the misery of mosquito-borne diseases almost anywhere,” said Eric Rasmussen in a related Focus.
“That is exciting news.”