Oct 27, 2014
Hot on the trail of the Asian tiger mosquito
Scientists use new discipline of landscape genetics to follow a ‘flying syringe’
By Diana Lutz
The Asian tiger mosquito (Aedes albopictus), which is native to Southeast Asia, was spotted in Houston in 1985. By 1986 it had reached St. Louis and Jacksonville, Fla. Today it can be found in all of the southern states and as far north as Maine.
An aggressive daytime biter, Ae. albopictus has an affinity for humans and is also a vector for human disease, said Kim Medley, PhD, interim director of the Tyson Research Center at Washington University in St. Louis.
The mosquito arrived in the U.S. in a shipment of used tires from Japan. Ae. albopictus lays eggs that can survive even if any water evaporates, so they’re very easy to transport, said Medley. “It’s widely accepted that global trade and travel have led to many species introductions,” she said.
“But how introduced species spread and adapt to novel conditions after introduction is less well understood,” she said.
To reconstruct what happened, Medley and her colleagues at the University of Central Florida turned to the new discipline of landscape genetics. Correlating genetic patterns with landscape patterns, they concluded that the mosquito had traveled by human-aided “jump” dispersal followed by slower regional spread.
The jumps occurred when mosquitoes hitched a ride in cars or trucks, traveling in style up major highways.
Their study, published in the Oct. 27 online edition of Molecular Ecology, is one of only a handful of landscape genetics studies to track an invasive species and the first to detect hitchhiking.
Medley’s concern is not that gardeners will be driven indoors but rather that human-aided dispersal will accelerate the adaptation of the mosquitoes and the viruses they can carry to their new surroundings and to one another.
So far this year the state of Florida has reported 11 cases of locally transmitted chickungunya, a disease original to Africa that wasn’t seen in the Americas until 2013.
“The movement of invasive species by human-aided transport can have far reaching consequences,” Medley said.
Read entire article at The Source.