A fungus weaponized with a spider toxin can kill malaria mosquitoes

MOSQUITO WATCH Entomologist Etienne Bilgo observes a mosquito breeding puddle inside a net-encased structure called the MosquitoSphere. Bilgo is part of a team that tested the ability of a genetically engineered fungus to kill mosquitoes that can spread malaria.
In field trials, genetically engineered Metarhizium pingshaense reduced numbers of the insects

By Tina Hesman Saey | ScienceNews

A fungus engineered to produce a spider toxin could help take down insecticide-resistant mosquitoes that can spread malaria.

In a netted, outdoor experiment in Burkina Faso, the genetically engineered fungus wiped out mosquito populations within two generations, researchers report in the May 31 Science. If the result holds up in a real-world situation, the modified fungus may one day become a tool for controlling mosquitoes that can transmit the deadly disease.

In 2017, an estimated 219 million people in 87 countries were infected with malaria, and 435,000 died, according to the World Health Organization. Africa carried most of the malaria burden, with 92 percent of cases and 93 percent of deaths occurring on the continent that year.

The fungus Metarhizium pingshaense, long known to infect and kill mosquitoes, was made even deadlier to the insects by the addition of a gene that produces a spider bite toxin called Hybrid. Researchers engineered the fungus to make Hybrid in the presence of the mosquito version of blood, called hemolymph. “We’re just bypassing the spider fangs and getting the fungus to do the same job,” says study coauthor Raymond St. Leger, an entomologist at the University of Maryland in College Park.

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