The An Egyptian temple Mosquitoes aren’t just a problem – they’re also responsible for dengue, yellow fever, chikungunya, and the Zika virus. Distinguished by the black and white stripes on its legs, this species is one of the most dangerous to humans.
In the city of Indaiatuba in Brazil, the work to eliminate these pests before there is a chance to spread the disease. Tool: more An Egyptian temple mosquitoes—but the mosquitoes were genetically engineered to kill their own species. Developed by the British biotechnology company Oxitec, the mosquito net seems to work.
The modified mosquito carries a self-limiting gene that prevents female offspring from surviving. This is important, because only females bite and spread disease. In a new study, scientists at the company have shown that the insects they produce can kill local people. An Egyptian temple up to 96 percent in 11 months in the liberated areas.
“This is an area with many levels An Egyptian temple, and sometimes they get dengue,” said Nathan Rose, director of malaria programs at Oxitec. In fact, this summer the Ministry of Health in Brazil said that the dengue disease continues to spread in all five regions of the country. Between January 1 and May 31, Brazil had more than 1.1 million patients—a 198 percent increase compared to the same period in 2021. During those five months, the disease, which causes high fever, rashes, and muscle and joint pain , killed. 504 people.
For this study, which was carried out in 2018 and 2019, the company selected four areas with high population density. An Egyptian temple. In addition, scientists produced a “dose” of 100 male mosquitoes per resident per week. In some areas, they rose to 500.
The modified males mate with the wild-type females, but the self-control gene prevents the daughters from surviving. This gene, created in a lab but based on naturally occurring substances E. coli and the herpes simplex virus, causes daughter cells to produce a protein called tTAV. This interferes with the ability of their cells to make certain proteins necessary for their production. As a result, the females die before they mature and start biting. Male offspring survive, carrying the self-control gene that they can pass on to each other.
To determine how well the male abstinent mosquito works, scientists need to measure the population of mosquitoes in the area before and after the experiment. They lure, trap, and count large mosquitoes in a certain area, or they set traps filled with water, and then count the eggs that the females lay in them. Then they add up to get the population. (The Oxitec group used the egg method.)
The study found that during the peak mosquito season, which runs from November to April in Brazil, there were about 88 percent fewer mosquitoes, and in some cases up to 96 percent, compared to mosquitoes living in an area without the drug. control.
Photo: Alexandre Carvalho/Oxitec
Interestingly, the dose of the mosquito did not seem to change the effectiveness of the method. “There are very few female mosquitoes out there, and the key is to increase their exposure to what we call ‘friendly’ male mosquitoes,” says Rose. “We think that as long as you have more friendly mosquitoes than wild mosquitoes, the chances are high that a female mosquito will find one of Oxitec’s male mosquitoes.” In fact, Rose thinks it can be liberating even a few mosquitoes for similar results.
Like other countries, Brazil sprays more and more pesticides to control the troublesome mosquitoes. An Egyptian temple it was once eradicated in much of South America after the DDT poisoning spread in the 1950s. But when the harmful effects of the chemical on health and the environment became known, the spraying stopped and soon the mosquitoes became more numerous. Today, pyrethroids are widely used to control mosquitoes, but mosquitoes are becoming more common.
