A scientific breakthrough in the Department of Evolutionary and Environmental Biology at the University of Haifa:
* A new study conducted at the University of Haifa has for the first time identified chemical substances that are secreted by the mosquitoes' natural predators and serve as warning signs for the mosquitoes*
A scientific breakthrough can help in the fight against mosquitoes: a new study conducted at the University of Haifa identified for the first time chemical substances that are secreted by the natural predators of the mosquitoes and serve as warning signs for the mosquitoes. Meaning: introducing these natural chemicals into the mosquito spawning areas will make the mosquitoes think that the water is infested with predators and prefer to stay away from there. The research will soon be published in the prestigious journal: Ecology Letters.
In the field of ecological and evolutionary research of predator-prey relationships, it is known that there are certain chemicals that the predators unconsciously secrete and are absorbed by their prey, thus serving as "warning signs" for the presence of the predators in the environment. However, the great difficulty in identifying those chemicals meant that until today scientists have not identified any such chemical. The new study, skin and tendon cream in Prof. Leon Blaustein's ecology laboratory, in the Department of Evolutionary and Environmental Biology at the University of Haifa. Together with Prof. Blaustein, PhD student Alon Zilbarbush and Dr. Shai Markman carried out the research in collaboration with Dr. Ephraim Levinson and Einat Bar, from the Agricultural Research Institute in Neve Yaer and Prof. Yoel Cohen from Rockefeller University in the United States.
This multidisciplinary research team has identified for the first time two chemicals that are secreted by an insect from the bedbug series called the stingray (scientific name Notonecta maculata) and absorbed by one of its main prey species, a species of mosquito (Culiseta longiareolata), one of the most common mosquito species in Israel.
In order to find the chemicals that serve as mosquito warning signs, the researchers first performed a series of chemical tests in the water where the predators swam and identified two chemicals that did not appear in the water where another mosquito predator swam, the dragonfly larva, which does not repel the same species of mosquito by chemical means, and also in water without predators at all. In another series of tests, the researchers examined whether these chemicals actually repel the mosquitoes: the researchers provided the mosquitoes with spawning pools that contained water with one of the chemicals, water with a combination of the two chemicals, a control group of water without either of the two chemicals, and water in which they had previously crawled. The tests included using concentrations of the chemicals that were identical to those secreted by the predator, at different times and during different interventions.
From the analysis of the data, it became clear that each of the chemicals individually lowers the amount of mosquitoes that came to breed in the water, when combining the two chemicals together created a repelling effect very similar to that created by the predator. The researchers also added that the fact that they used synthetic chemicals in their experiment, produced in a laboratory, further strengthens the claim that the mosquitoes were repelled by the chemical and not by another biological component that may have been present in the water but was not detected by them.
According to Prof. Blaustein, their identification could be a breakthrough in the creation of a natural and environmentally friendly mosquito repellent. Unlike the mosquito repellents that exist today that are applied to the skin or are supposed to repel the mosquito from entering the house, a mosquito repellent based on these natural chemicals will prevent the mosquitoes from reaching the breeding area at all.
Also, many of the chemicals that are introduced into water bodies where mosquitoes spawn are toxic not only to mosquitoes but also to wildlife and humans. "Most of the mosquito repellents that exist today are not environmentally friendly and mosquitoes develop resistance to them relatively quickly. I would not recommend rushing and throwing away the materials that exist today, but of course the best prevention is to prevent mosquitoes from reaching populated areas at all. In addition, our breakthrough will help understand predator mechanisms - Predation of other species", Prof. Blaustein concluded.