Scientists at Boğaziçi University in Istanbul are working to develop a biopesticide against the Asian tiger mosquito, an invasive species that acts as a vector for a variety of diseases such as dengue fever, Zika and the West Nile virus.
Asian tiger mosquitoes have become a common sight in Turkey in recent years, and studies have shown that they have developed immunity to chemical pesticides. The mosquitoes were originally bred in subtropical climates such as northern China and central Japan, but gradually spread to North America and Europe.
Necla Birgül Iyison, a member of the University’s Department of Molecular Biology and Genetics, and her team are working on the new pesticide. Iyison said the species recently invaded Istanbul and is “very aggressive” in nature, stating, “It can even bite you through clothing and transmit a number of diseases. The mosquitoes have developed a resistance to chemical solutions. We are now working on a biological agent. A certain type of bacteria is injected into their larvae and once the larvae are fed to them, it is activated and eventually kills them. We are currently producing the bacterial protein in our laboratory, ”she told the Demirören News Agency (DHA) on Monday.
In recent years, a similar technique has been tested in China on mosquitoes infected with a virus-fighting bacterium before zapping them with a small dose of radiation, the zapping being designed to sterilize the mosquitoes. Once the mosquitoes were infected with the strain of bacteria (not found in wild mosquitoes) it would prevent them from reproducing, as mosquitoes must be of the same type to ensure the survival of their young. In 2016 and 2017, the team led by Zhiyong Xi at Michigan State University released male mosquitoes for 18 weeks on two islets near Guangzhou, China, a dengue-infested region. The number of female mosquitoes, responsible for the spread of disease, fell 83% to 94% each year, similar to other methods like spraying insecticides and using genetically modified mosquitoes. In a few weeks there was no sign of pathogenic mosquitoes at all.
According to experts, mosquitoes can transmit more than 20 deadly viruses. Soeren Metelmann, a scientist at the University of Liverpool in the UK, recently told the Anadolu Agency (AA) that countries like Italy, France and Spain could not eliminate the species and are now focusing on reducing their numbers and increasing their impact minimize. “This species has the advantage of being able to lay special eggs at the end of the year that can simply wait until winter is over and then hatch the larvae when spring temperatures are more suitable,” he said. Metelmann predicted that an impending climate crisis leading to warmer temperatures could play a role in the spread of mosquito-borne infections. “In warmer temperatures, there are more mosquitos and they become contagious much faster, making for perfect outbreak conditions,” he said.