Two UN agencies have developed a new technology involving ionizing radiation as a weapon in the fight against mosquitoes carrying Zika and other diseases, an expert said Wednesday.
The Sterile Insect Technique (SIT), jointly developed by the Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA), uses radiation to sterilize male pests, which are mass produced in special rearing facilities, Qu Liang, director of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, told Xinhua in an interview.
“Large numbers of sterile males are then released systematically over a target area, where these sterile males mate with wild females. No offspring are produced, and as sterile males gradually outnumber fertile ones, the wild mosquito population declines over time,” he said.
The IAEA and FAO have teamed up since 1964 to seek the application of nuclear techniques in food and agriculture, with specific programs on insect pest control, soil and water, plant breeding, livestock, and food and environment.
SIT, which is not only effective against mosquitoes, has already been deployed in more than 20 countries worldwide.
It has been particularly successful in areas with isolated insect populations, where wild fertile females cannot fly in from neighboring regions to re-establish new populations, Qu said.
However, rolling it out against mosquitoes would pose a new set of challenges.
Qu explained that although sterile male releases can focus on urban and suburban areas where the human population is concentrated, wild males are harder to crowd out as mosquitoes are far more widespread.
This means that SIT would also be applied in combination with other control methods. It will make SIT more effective and efficient in reducing the mosquito population with conventional methods before sterile releases.
Due to the increasing burden and costs of mosquito-transmitted diseases, in part because of globalization and climate change, the need for SIT is growing, Qu said.
“The successive fights against dengue, chikungunya and Zika have shown that conventional control tools, such as insecticides, are becoming less effective due to mosquitoes developing resistance,” he said. “With no effective vaccines, the best line of defense is therefore to combat the mosquitoes themselves.”
“This is where SIT can be an effective, safe, cost-effective and bio-secure complementary tool. SIT is safe both for the environment and for people. In addition, insect pests cannot develop resistance to SIT,” he added.
Qu said a lot of research has already been carried out at the Joint IAEA/FAO Insect Pest Control Laboratory in Seibersdorf, Austria, as to how SIT can be used to fight mosquitoes, including the Aedes Aegypti.
Pilot projects are under way in China and Mauritius to validate the technology, with one in Italy already having been successfully completed.
“Preliminary work for site selection, population surveillance, and quality control is well advanced in certain member states,” said Qu.