A fungus – genetically enhanced to produce spider toxin – can rapidly kill huge numbers of the mosquitoes that spread malaria, a study suggests.
Trials, which took place in Burkina Faso, showed mosquito populations collapsed by 99% within 45 days.
The researchers say their aim is not to make the insects extinct but to help stop the spread of malaria.
The disease, which is spread when female mosquitoes drink blood, kills more than 400,000 people per year.
They turned to a toxin found in the venom of a species of funnel-web spider in Australia.
The genetic instructions for making the toxin were added to the fungus’s own genetic code so it would start making the toxin once it was inside a mosquito.
“A spider uses its fangs to pierce the skin of insects and inject toxins, we replaced the fangs of spider with Metarhizium,” Prof St Leger explained.
The results, published in the journal Science, showed numbers soared when the insects were left alone. But when the spider-toxin fungus was used, there were just 13 mosquitoes left after 45 days.
“The transgenic fungus quickly collapsed the mosquito population in just two generations,” said Dr Brian Lovett, from the University of Maryland.
“The prospects for controlling mosquitoes using this modified fungus are high.
“Proportionate bio-safety regulations are needed to ensure that the viability of this and other approaches for vector [mosquito] control using genetic methods are not lost through overly zealous restrictions.”
Dr Tony Nolan, from the Liverpool School of Tropical Medicine, added: “These results are encouraging.
“We need new and complementary tools to augment existing control methods, which are being affected by the development of insecticide-resistance.”