The use of drones can significantly increase efficiency and reduce costs in the application of nuclear technology to curb disease-carrying mosquitoes, according to a study by the International Atomic Energy Agency. The discovery marks an important step in the large-scale deployment of this approach to control dengue, yellow fever and Zika virus hosts.
The drone, called Romeo, is helping to save human lives by controlling the number of mosquitoes that spread the disease. The International Atomic Energy Agency has successfully tested drones to reduce the number of mosquitoes that transmit the disease, and the technology is expected to be rolled out in Brazil next year. INTERNATIONAL ATOMIC ENERGY AGENCY PHOTO/N. CULBERT
The study, published this week in the journal Science Robotics, tests the effectiveness of using drones to release sterile mosquitoes. Insect infertility techniques, designed to sterilise insects, have been used successfully for decades to combat agricultural pests such as Mediterranean fruit flies and tsetse flies. Scientists have been working in recent years to develop new ways to fight mosquitoes.
Insect infertility techniques use radiation to sterilize large numbers of male insects and then release them to mate with wild females. Since these insects do not produce any offspring, the number of insects decreases over time.
The method requires the even release of a large number of sterile male insects under good conditions in order to compete with wild male insects. The drone’s prototype, tested in Brazil in April 2018, can carry up to 50,000 sterilized mosquitoes on each flight and release them within 10 minutes without loss of mosquito mass to more than 20 hectares of land.
The new discovery represents a major breakthrough in expanding the use of insect infertility technologies, said Buyer, a medical entomologist at FAO’s joint project with the IAEA OnA’s Joint Project on Food and Agriculture Nuclear Technology.
Mosquitoes have long and fragile legs and their wings can be easily broken. If other sterile insects are released, they are usually released from the air using aircraft or small rotors, but using this method to release mosquitoes can easily harm them. So far, the release of sterile male mosquitoes has been released from the ground, a labor-intensive, time-consuming and expensive method.
Mr Bouye said that if ground-based releases were carried out, the drone would need two hours and twice as much human resources to fly in the 10-minute area covered by the drone.
The World Health Organization estimates that vector-borne diseases account for 17 per cent of infectious diseases and kill more than 1 million people each year, but countries often lack resources for large-scale mosquito eradication programmes.
Eric Rasmussen of the University of Washington School of Public Health said in a commentary published in the journal Scientific Robotics that the new study shows progress is critical to achieving more cost-effective mosquito control methods.
Bue, a medical entomologist with the Joint Project on Food and Agriculture Nuclear Technology, said the field work to test drones has an added benefit of proving that mosquitoes that use radiation methods for sterilization are competitive compared to wild male mosquitoes when mating with wild females.
The International Atomic Energy Agency and its partners are now working on the development of a small drone that can carry about 30,000 mosquitoes. This is crucial, Bouye said, because light aircraft meet strict rules for drone flights in urban areas, where the disease-transmitting Aedes aegypti mosquito is often concentrated.
As part of the integrated mosquito control package, the International Atomic Energy Agency is also working to improve methods to distinguish between male and female insects during large-scale breeding. The key steps to this process are still done manually, which increases costs. Separation is important to ensure that female mosquitoes are not released because they can bite and spread disease.
Mosquitoes in the lab: Removing static water from mosquitoes can help prevent the spread of the Zika virus. FAO Photo/Simon Miana