Culex larvae (Wikipedia)
AUSTRALIAN researchers have raised concerns about the spread of disease by a type of mosquito known as the London Underground mosquito.
The Culex molestus mosquito first fed on Londoners seeking shelter in the Underground during the Blitz in WWII, before hitching a ride to Australia on American soldiers during the 1940s.
It is now believed to be spreading diseases such as Ross River virus and Barmah Forest virus Down Under, according to entomologist Dr Cameron Webb.
Dr Webb published his findings with colleagues in this month’s Journal of Vector Ecology.
“One of the most important findings of this study was that … the mosquito remains active over cooler months, whereas almost all other mosquitoes disappear during winter,” Dr Webb said.
“The mosquito is unique in that it prefers to live in underground environments but there are now concerns regarding the role this mosquito may play in the transmission of mosquito-borne viruses in Australian cities.”
Dr Webb and his colleagues spent two years researching the breeding of the Underground mosquito in public park toilet blocks and flooded stormwater drains.
“Working around toilet blocks in public parks is not behaviour I’m usually engaged in when catching mosquitoes, but it proved to be a worthwhile exercise,” Dr Webb said.
Dr Webb said the Culex molestus was unusual, in that the mosquito does not need to feast on human blood until after the first batch of eggs is laid. Unlike other mosquitos who need protein obtained from blood before they are able to develop eggs, this type mosquito relies on existing nutrient stores.
This behaviour may have helped it adapt to breeding underground, according to Dr Webb.
“It’s really single minded, it just wants to lay its first batch of eggs before it heads off looking for a host to feed in,” Dr Webb said.
“I think it explains how this mosquito has adapted to exploit these underground water-holding containers that we find them in.”
Dr Webb says the findings have implications for the design of cities and residential developments.
“The results … indicate that Culex molestus is perfectly adapted to subterranean habitats in close association with human habitation,” said the study.