Scientists believe they have found a unique way to fight mosquito- borne diseases, including diseases such as dengue, yellow fever and Zika. Their method is to numb the male mosquitoes to mating with the female mosquitoes, which makes it difficult for them to chase the female mosquitoes. Mosquitoes establish sex while flying in the air, and male mosquitoes identify a female by listening to the sound of her wings flapping, which attracts the female.
The researchers conducted an experiment in which they changed the pathway of the hearing gene of male mosquitoes. The result of this change was that, even after three days in the same cage, the male mosquitoes did not make physical contact with the female mosquitoes. Female mosquitoes transmit disease, so preventing their fertility can help reduce all mosquito populations.
A research team from the University of California, Santa Barbara was studying Aedes aegypti mosquitoes, which transmit the virus to about 400 million people each year. The team made in- depth observations of mosquitoes’ aerial courtship – which can last from seconds to a minute – and then used genetics to disrupt it. They focused on a protein called ‘trpVa’, which is crucial for the hearing process.
Mosquitoes with the altered gene lost the reflexes in their brains, making it impossible for them to listen to the sound of wings of potential mates. Because of this, they could never mate. In contrast, wild- type (non- mutant) male mosquitoes mated rapidly and fertilized nearly all of the females in their cages.
According to researchers from the University of Santa Barbara, the effect of the ‘knock- out’ effect of this gene was “absolutely complete”, as the numbed male mosquitoes stopped mating altogether. University of Oldenburg, Germany Dr. Joerg Albert, who is an expert on the romance of mosquitoes, expressed his opinion about this research. They feel that hearing attack is a promising method for mosquito control, but it needs proper study and management.
“This research provides the first direct molecular test, suggesting that hearing is not only important for mosquito reproduction, but is essential. If male mosquitoes lacked the ability to hear and chase female mosquitoes – female mosquitoes would cease to exist.”
Another method being studied involves releasing uninfected male mosquitoes into areas where mosquito- borne diseases are spreading. Although mosquitoes spread disease, they are an important part of the food chain, providing food sources for fish, birds, bats, and frogs, and some mosquitoes are important pollinators.