Mosquitoes near missing on 2 Chinese islands

Researchers are not the first to try to reduce mosquito populations around the world. In 2018, scientists at the Imperial College of London used gene editing tools to make female mosquitoes infertile, while men developed normally and continued to propagate the genetic mutation.

One of the researchers of the Chinese study, Xi Zhiyong, a professor at Michigan State University, is a longtime pioneer in this field of study. Leading a mosquito factory in southern China, he had previously attempted to use sterilized male mosquitoes to mate with unchanged females.

"We are building good mosquitoes that can help us fight the bad guys," Xi told CNN in 2016.

In the new study published by the International Journal of Science, Xi and his colleagues have tried to further reduce the number of mosquitoes by limiting the reproductive capacity of men and women.

Female mosquitoes were sterilized with low intensity radiation while males were infected with Wolbachia bacteria, and both were released during the peak breeding season in 2016 and 2017 on two islands near Guangzhou City.

The results were so convincing that they almost completely eradicated the female mosquito population on both islands.

In a statement, mosquito ecologist Peter Armbruster said the trial was one of the most successful mosquito reduction trials to date, given the persistent survival capacity of mosquitoes .

Experts said that Asian tiger mosquitoes are particularly difficult to eradicate with the help of conventional methods of population control, such as pesticides and the elimination of stagnant water where insects lay eggs their eggs.

White-striped mosquitoes have been described as "highly invasive" and have spread from Asia to almost every continent in the last 40 years, according to the study's authors.

Mosquitoes pose serious threats to human health, beyond irritating stings. The World Health Organization (WHO) has described insects as "one of the most lethal animals in the world", because of their ability to quickly spread deadly diseases such as dengue fever and malaria .

In Guangzhou, a densely populated urban metropolis with a tropical climate, about 37,350 people were infected with dengue fever during an epidemic in 2014.

This month, health authorities in the Philippines declared a "national dengue alert" after more than 450 people died of the virus in the first half of 2019.

According to the International Journal of Science, there is currently no vaccine or effective treatment for most mosquito-borne diseases. Control of insect populations is therefore one of the most effective control methods.

"A new tool such as what is described in this document is really needed," Dobson said.