Londoners have a complex relationship with creatures that live below ground. The Tube mice are heroes, covered in soot, they scurry around like frantic tourists late for their plane. Rats, on the other hand, are to be shunned and feared while foxes straddle the love-hate barrier.
One specialist London flier is more in the loathed rat category. It is the mosquito and, remarkably, there is a distinct species that dwells on the underground – although now it has found its way around the world.
It was named– appropriately – as Culex molestus and forms a distinct species from Culex pipiens. It is now known by its name of the London Underground mosquito and is believed to have diverged when a colony was sealed within the Tube system although some contend they arrived in fruit from the Docks.
It was first widely reported during the Blitz of World War Two. A voracious attacker, it feasted on the the blood of those who had sought shelter from German bombs underground.
Half a century later, Katharine Byrne carried out more work on the mosquito which, she discovered, had adapted to feed on mammals and humans – as opposed to birds – and lost the instinct to hibernate because there were no seasons.
Although the species is now widespread in similar environments across the world, an exploration of its DNA suggests that it first evolved in London, an example of speciation that, in other animals and places, can take tens of thousands of years.