The male on the left won’t bite, but the female on the right certainly will! Image: CSIRO
There are plenty of reasons to hate mosquitoes. They are annoying, hard to catch, and their bites can itch for days. But they’re not just irritating – in many places they spread diseases such as malaria, Zika and dengue.
Mosquitoes infect around 700 million people each year, and these infections cause hundreds of thousands of deaths. So you might be surprised to hear that CSIRO’s been releasing millions of mosquitoes along the Cassowary Coast in north Queensland. Even stranger, the locals have been helping out!
Our mosquito releases are actually a trial of anti-mosquito technology. And the mosquitoes we’re releasing are not as bad as most. We’re only releasing male mosquitoes, and males don’t bite. Instead, they drink nectar, fly around looking for a mate, and then die.
The males we’re releasing have been treated with a bacteria called Wolbachia, which is harmless for humans, but has a strange effect on these mosquitoes. When one of these male mosquitoes mates with a wild female, none of the eggs will hatch.
That’s the key to the project. If we can make sure the local females mate with these special males, then boom! No more ‘baby’ mosquitoes, which means in a few weeks’ time, no more adult mosquitoes. At this stage, there’s no way to get rid of all the local males. The best we can do is try to crowd them out.
It’s a mammoth task. We’ve been working with James Cook University and QIMR Berghofer to breed around 20 million mosquitoes.
Then we need to sort them so we release just the males. Luckily, a company named Verily has mosquito sorting technologies that make the task a lot easier.
The early results are promising. During the trial, the population of wild mosquitoes dropped by more than 80%. With some improvements, this technique might make pesky mozzies history!
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