Fatal Attraction: Engineered Male Mosquitoes Could Transform Disease Control
A revolutionary pest control method turns male insects into allies against disease by engineering them to produce proteins that reduce female lifespan after mating, potentially transforming the global fight against mosquito-borne diseases.
First published by Macquarie University
Fatal Attraction: Engineered Male Mosquitoes Could Transform Disease Control
Scientists at Macquarie University have developed a new way to control disease-carrying insects using a fast, targeted and ingenious technique turning male insects into subversive population controllers.
The research, piloted in fruit flies, could have far-reaching impacts on global health if applied to disease-carrying insects including mosquitoes.
Their invention, named the Toxic Male Technique (TMT), involves genetically engineering male insects to produce insecticidal proteins in their reproductive system that significantly reduce female lifespans after mating. It’s a major breakthrough that works faster than any other approach using genetic engineered insects for population suppression.
Synthetic biologist Sam Beach, a PhD candidate from Applied BioSciences at Macquarie University and the ARC Centre of Excellence in Synthetic Biology, is lead author of the study published on 7 January in Nature Communications.
“By targeting the female mosquitoes themselves rather than their offspring, TMT is the first biocontrol technology that could work as quickly as pesticides without also harming beneficial species,” says Beach.
This matters because only female mosquitoes bite humans and spread diseases.
When female mosquitoes mate with these engineered "toxic males", they receive proteins that dramatically reduce how long they live.
In lab tests using fruit flies, females that mated with TMT males died 37-64 per cent sooner than those mating with non-engineered males.
Rigorous safety testing
The team note this process is less environmentally destructive than spraying chemical pesticides which often also kill beneficial species, as TMT only affects the specific pest species being targeted.
“We specifically chose venom proteins that have targets unique to invertebrates, so they aren’t toxic to mammals and are unlikely to harm beneficial insects that might eat these males," says supervising co-author Associate Professor Maciej Maselko, who heads the Applied BioSciences Maselko Lab.
The research comes at a critical time, as mosquito-borne diseases reach record levels worldwide.
One mosquito species alone, Aedes aegypti, infects 390 million people with dengue fever each year. Meanwhile, malaria - spread by several other mosquito species - kills over 600,000 people annually.
Current genetic control methods are slower, reducing mosquito populations gradually across generations. Under these existing techniques, when females mate with the genetically modified males, they either produce fewer offspring or give birth only to males.
However, the natural lifespan of an Aedes aegypti female mosquito is around three weeks, so current genetic methods allow adult females to continue to buzz around spreading disease far longer before these mosquitoes die.
Slash disease spread
Computer models suggest that using TMT on Aedes aegypti mosquitoes could slash their disease-spreading biting rates by 40-60 percent compared to existing methods.
“As we've learned from COVID-19, reducing the spread of these diseases as quickly as possible is important to prevent epidemics,” says Beach.
The technique isn't just for mosquitoes. Insect pests and diseases destroy 20 to 30 per cent of the world's major food crops, and the damage they cause quadruples in cost every decade. TMT could offer farmers a precise tool to protect crops without harming beneficial insects like bees.
Before these engineered males can be released into the wild, more testing is needed.
"Our current results demonstrate the proof of concept for TMT in fruit flies. We still need to implement it in mosquitoes and conduct rigorous safety testing to ensure there are no risks to humans or other non-target species," says Associate Professor Maselko.
“We expect it will take three to five years before we see this technique applied,” says Associate Professor Maselko.
“If all goes well, we’ll have it working well in mosquitoes in a year or two and then get it to field trials after that.”
