Find four natural substances that kill insects

Scientists at the University of California (USA) said they have found four natural killer mosquitoes that replace DEET, a compound that has been used since World War 2.

The current release is published in the journal Nature (October 2).

DEET - short for diethyl-meta-toluamide - was first used by the US Army in 1946 after soldiers deployed in the Pacific region suffered from dengue fever and other diseases caused by mosquitoes.

These insecticides are still commonly used, but they also have certain limitations.

Due to the high price but need to be used on a regular basis, DEET is not used to prevent disease in dengue outbreaks or places. In addition, it can decompose some types of plastics, synthetic fibers and paint surfaces.

Photo: npic.orst.edu

More worrisome, the evidence suggests that some flies and mosquitoes exhibit drug resistance and that this chemical also breaks down an important enzyme (called axetylcholinexteraza ) in the animals' nervous system. breast.

Four new insecticides replaced DEET after scientists conducted a combination of entomology and data calculations.

The first step is to find out how mosquitoes sense DEET and be destroyed by this drug. To do this, they conducted research on an insect with the family of mosquitoes, the fruit fly (Drosophila melanogaster), one of the most common organisms in the laboratory.

The results showed that fruit flies used an receptor called IR40a within the concave nervous system cells in its antenna.

The next step is to find a suitable aromatic molecule that can activate this receptor. It must be a natural compound that can be found in fruits, trees or animals.

Of the approximately half a million initial compounds, scientists selected nearly 200, then continued to select the 10 most feasible compounds and experiment them in fruit flies. Among them, eight compounds are shown to be effective insecticides.

Next, four of these eight compounds were tested on mosquitoes and all showed good results. Fortunately, three of the four categories have been approved by the Food and Drug Administration (FDA) as food additives or flavorings, meaning they are safe for humans. These three compounds are called dimethyl anthranilate, ethyl anthranilate and butyl anthranilate , which can be impregnated with insects, clothing, blankets and nets.

These substances also do not degrade plastic, are easy to use and have a pleasant smell like grape smell. Scientists emphasize that this study opens up the prospect of producing cheaper new disinfectants that protect people from insect-borne diseases worldwide, as well as help protect animals and crops.