The researchers were shocked to find highly resistant yellow fever mosquitoes

Mainly Japanese scientists publish their findings in the scientific journal Science advances. And 78 percent describe it as “shocking” and fear that this will jeopardize protection programs against diseases spread by mosquitoes.

Insects can only survive pesticides if they can adapt quickly enough genetically. Here’s what happens: Researchers have identified a total of ten new subspecies of yellow fever mosquitoes, which possess a mutant variant – called L982W – that has extremely high resistance in the laboratory to the most powerful and widely used pesticides. Other species contained combinations of genetic mutations, which also gave them more resistance. While the authors note that L982W has not been found outside of Vietnam and Cambodia, they fear that the mutation could slowly spread to other parts of Asia.

Sander Koenrat, assistant professor of medical and veterinary entomology at Wageningen University (WWR), knows the mechanism of genetic mutation by which insects increase their resistance, but he is amazed at the high rate and the fact that the researchers discovered so many mutations that increase insect resistance increase mosquitoes.

Backfire

Koinratt also rightly describes the fear that this genetic mutation will spread to more parts of Asia, as long as countries continue to use the same pesticides. I’ve already seen mosquito resistance build up in recent years: every year mutations appear that cause new resistance.

According to Konrat, findings like those of the Japanese researchers essentially show that ‘long-term use of the same chemical insecticides is not a sustainable method of insect control. It’s a kind of arms race that has the opposite effect.

Refers to research into alternatives to pesticides. For example, you can put mosquito traps. When we adequately understand flight behavior and the impact of odors that attract mosquito species, the extensive use of mosquito traps can produce positive results.

Another method is to spread mosquitoes infected with Wolbachia, a bacterium that mosquitoes pass on to each other through the maternal line. This has two effects: in the males, the bacteria produce sterile offspring, while the females become insensitive to viruses such as the dengue virus. Koenrat: “In Australia, Indonesia and Brazil, the tests have already been done with good results.”

To do that, you first have to release the mosquitoes, which seems counterintuitive in controlling disease-spreading mosquitoes, but according to Koenrat, there’s no way around it. And more sustainable: With this approach, you can attack one species of mosquito specifically. There are always side effects with insecticides: you also destroy other insects that are not at all harmful.