Summary: Tech company grows sterilised Self-Limiting Mosquitoes that mate but leave no offspring. Will this biological control end the spread of diseases transferred by mosquitoes?
SDG 2030: Goal 3 Good health and well-being
Founder: Simon Werner
Where: India, Brazil, Cayman, Florida and Panama
Impact: Hundreds of millions of households in five countries
By Gillis Kersting
Zika, malaria, dengue and yellow fever. These are just a few diseases unleashed by stings of aedes aegypti, the deadliest creature on Earth. This particular mosquito kills over a million people every year and annually causes illness to hundreds of millions more. Demographers argue that throughout the ages infectious disease, caused by mosquitoes, claimed more deaths than all wars in history combined.
Oxitec gives killer mosquitoes a taste of their own medicine
To end this terror British tech company Oxitec in 2002 developed Self-Limiting Mosquitoes. These lab-grown insects, bred in Oxford and Brazil, are sterilised and given a self-limiting gene. When the male Self-Limiting Mosquitoes –females are prematurely done away with- are set out in the wild, they mate but their offspring will never see the light of day.
According to Oxitec, their method of biological control is available at relatively low costs, since mosquitoes are cheap to export. Moreover Oxitec’s ‘Operation Romeo’ doesn’t rely on chemical pesticides (to which mosquitoes by now are resistent anyway).
Similar attempts at biological control have been tried with mixed success. Mosquitofish, who eat 500 mosquito larvae per day, helped the Soviets clear their Black Sea coast from malaria in the 1950’s. As a token of appreciation the city of Sochi built a monument in 2008 to honour the mosquitofish. On the other hand, when in 1925 the same mosquitofish were unleashed in Australian waters, events took a turn for the worse. The supposed to be control agents aggressively disrupted the maritime ecosystem and chased away other species who lived of mosquitoes. As a matter of fact, the introduction of mosquitofish may have exacerbated Australia’s mosquito problem.
Simon Werner, founder of Oxitec, knows why: ’Mosquitoes are highly unpredictable in choosing their breeding place. Therefore predators can’t find mosquito larvae all the time. In sterilising males we bypassed this obstacle to biological control.’ Next concern, however, is a technical one. Just as humans, female mosquitoes are more attracted to wild males than to their lab-grown counterparts, which are weaker and slower. Also antibiotics such as tetracycline, used in sterilising mosquitoes, may allow for bacteria to develop immune genes inside the insects.
To critics who fear that taking out all mosquitoes would disrupt the food chain, Simon stands assured: ‘Even if mosquitoes were to be extinct, other insects will replace them in the food chain.’
Apart from migrating birds in the Arctic tundra who depend on mosquitoes, no one will miss them.