Malaria, Zika virus, dengue, sleeping sickness… some people get goose bumps just hearing these names. Dr. Jérémy Bouyer certainly isn’t one of them. He received funding from the ERC to look for environmentally-friendly techniques against pest insects that transmit diseases to human and animals and can damage crop production. And he does so, with the help of drones…
Pesticides have toxic effects on living species, plus they pollute the planet. Finding environment-friendly alternatives that are not harmful for health and for the environment is at the core of Jérémy's Bouyer research - at the FAO-IAEA Insect Pest Control Laboratory - currently tackling three specific types of pests: mosquitoes, tsetse flies and Mediterranean fruit flies.
Bouyer's approach is at the crossroads of basic and applied research. It consists of improving the existing "sterile insect technique" which involves raising male insects in the lab and sterilizing them by radiation. The principle is simple: once the sterilized males are released into the environment, they compete with other males to fertilise the wild females of their own species. This sterile pairing reduces the fertility of the overall population. Over time, the insect population declines and collapses.
The EU-funded researcher introduced two major novelties to this technique. Not only do the unfertile male insects pair with wild females, they also transmit biocides and densoviruses that kill the progeny of any females that may have escaped their advances.
This is a very interesting method from an eco-friendly perspective, as these specific viruses and biocides will only affect the targeted species and their eggs, preserving the good health of other insectsThanks to his long experience in the field, Bouyer also identified and tackled a major obstacle to his boosted sterile insect technique. To make sure that the unfertile males can successfully compete with their wild peers, they need to be in good shape and to reach extended areas.
"Until now, the main bottleneck of this technique was the release of the insects. Mosquitoes, for instance, are extremely fragile. They do not support any pressure and could only be released from the ground. During its whole life, a mosquito will not travel more than 100 metres away from its place of birth. In other words, to release sterilized insects over wide areas, we needed many simultaneous points of release. This is costly and time-consuming", explains Bouyer.
In partnership with the Food and Agriculture Organization of the United Nations (FAO) and WeRobotics, a Swiss-American non-profit group, Bouyer developed an innovative system using drones to release the insects over wide and populated areas. Each machine can carry more than 50,000 mosquitoes per flight and treat twenty hectares in five minutes. It is equipped with a specially-designed system that allows for transport and release without harming the animal. The method is fast, cheap, safe and adaptable to an array of insects.
"Last April, we successfully tested the system in Brazil, in partnership with Moscamed. Our objective now is to improve the capacity of the drones to carry up to 150,000 mosquitoes. We also aim to make them lighter, so they can be used safely over densely populated areas".