As if blood-sucking insects weren't nasty enough, Australian researchers have discovered an offshoot of the Culex molestus mosquito that has adapted to urban environments, breeding and lurking about in dark crevices and pipes found beneath cities. And unlike other mosquitoes, this one can lay its eggs before requiring its first blood feast.
Most species of mosquitoes breed in ponds, pools, or wetlands, but the variant of a mosquito introduced to Australia in the 1940s has adapted to life underground, exploiting septic tanks and used stormwater pipes for its reproductive needs. The discovery, which was made by Cameron Webb from Sydney Medical School, has prompted calls for the redesign of water storage systems. The fear is that, quite unknowingly, urban planners are creating new opportunities for mosquitos to reproduce – a development that could result in not just the spreading of opportunistic mosquitoes, but diseases as well.
The find also shows the tremendous resilience exhibited by mosquitoes when it comes to adapting to changing environments. Mosquitoes have been found in a wide range of ecological niches, including coastal rock pools and alpine snowmelt pools.
According to Webb, the mosquito was difficult to trace. He and his team had to snoop around stormwater drains and other polluted structures for two years to do their investigations. But when they reached toilet blocks in urban parklands, they hit the jackpot. Disused septic tanks appear to be the maternity ward of choice for this particular mosquito.
What the researchers also discovered was that this offshoot of Culex molestus, unlike other mosquitoes, can lay a batch of eggs prior to having a blood meal. Most mosquitoes need blood to develop their eggs, but the females of this species can lay an entire batch by using nutrients stored earlier in its life cycle – a process that's known as autogeny.
This adaptation is likely the result of the mosquito having to deal with a shortage of suitable animals to feast upon given its subterranean stomping grounds. The biological trick also allows it to live and breed all-year round. Webb believes this is the only Australian species that can do this.
Underground mosquitoes aren't a new phenomenon. Back during World War II, a similar kind of mosquito made a meal of Londoners hiding underground during the Blitz, what they referred to as the London Underground Mosquito. As if they didn't have enough to worry about.
The entire study can be read here.
Image via Shutterstock.com/Natursports.