Venomous male mosquitoes will poison females with their sperm in a new population control method developed by Australian researchers.
The method involves genetically engineering males to produce proteins from spider and sea anemone venom, which they inject into females during mating, shortening their lifespan.
Researchers from Macquarie University have tested the ‘poisonous male technique’ on a species of mosquito that spreads dengue, Zika and other viruses, following a study on fruit flies. published in the peer-reviewed journal Nature Communications.
Lead author Sam Beach said the species-specific approach could be used to quickly suppress outbreaks of mosquito-borne diseases such as dengue fever – which leads to 390 million cases worldwide every year – without having to spray huge amounts of insecticides that damage the can prevent disease. decimating local insects.
“Ideally what we’re trying to achieve is: a male mosquito mates with a female and then she dies immediately,” he said.
Injecting a new gene into freshly laid mosquito eggs using tiny glass needles was “a very laborious process,” he added.
Only female mosquitoes are blood feeders. They generally mate within 24 to 48 hours after hatching, but can live for several weeks and continue biting, allowing the continued spread of disease.
According to the study, the toxic male technique could reduce blood flow by 40% to 60%.
While other approaches to genetic biocontrol have used males to reduce the viability, blood-feeding or disease transmission of mosquito offspring, Beach said the new method targeted females directly.
“With this approach we can immediately reduce the size of the female mosquito population and then hopefully achieve a very rapid reduction in the spread of these vector-borne diseases.”
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An evolutionary biologist from the University of Melbourne, Dr Tom Schmidt, who was not involved in the study, said pesticide resistance is a global problem, prompting scientists to develop other approaches to pest control.
“Mosquitoes are becoming resistant to insecticides very quickly and can spread resistance,” he said. “They can develop it, and they can also spread it by getting on boats and airplanes and spreading it all over the world.”
An Australian approach that involved infecting mosquitoes with Wolbachia bacteria dramatically reduced dengue transmission in northern Queensland, he said. Genetic approaches could also work, he said, noting that mosquito control was not a one-size-fits-all approach.
The climate crisis also caused mosquito species to appear in places they had never been before.
Professor Philip Weinstein, an infectious disease researcher at the University of Adelaide who was not involved in the study, said there are thousands of species of mosquitoes but only a few transmit diseases.
Weinstein said an ideal solution would be to control the insects without eradicating them, as mosquitoes are pollinators and an important food source for fish and bats.
“Ecosystem health – things that happen in the environment, including mosquitoes, but also water quality, air quality, climate change, biodiversity loss – all influence, directly or indirectly, impacts on human health,” he said.