An invasive disease-carrying mosquito has spread to the Rocky Mountains

This is the original story It appeared on Inside Climate News and is part of the Climate Desk collaboration.

It can be a carrier of life-threatening diseases. It is hard to find and hard to kill. And he is obsessed with human blood.

Aedes aegypti is a species of mosquito that people like Tim Moore, district manager of a mosquito control district in Colorado’s Western Slopes, really don’t want to see.

“My son,” said Moore, “they are locked up among men.” “It’s their blood meal.”

The mosquito species is native to tropical and subtropical climates, but as temperatures rise and precipitation patterns change, Aedes aegypti — which can spread Zika, dengue, chikungunya and other potentially deadly viruses — is on the move.

It appears throughout the Mountain West, where conditions have historically been too harsh for it to survive. Over the past decade, cities in New Mexico and Utah have begun catching Aedes aegypti in their traps year after year, and just this summer, one was found in Idaho for the first time.

Now, an old residential neighborhood in Grand Junction, Colorado, has emerged as one of the last frontiers for this pesky mosquito.

With a population of about 70,000, it is the largest city in Colorado west of the Continental Divide. In 2019, the local mosquito control district observed a recalcitrant Aedes aegypti in a trap. Strangely, mosquitoes had already been found in Moab, Utah, about 100 miles to the southwest. Moore, the district manager, concluded that they had caught a traveler and that the harsh climate of Colorado would quickly kill the species.

“I came to the conclusion that this is a one-off, and we shouldn’t worry too much about it,” Moore said.

Tim Moore, director of the Grand River Mosquito Control District, explains that managing a new invasive mosquito species in Grand Junction has required the district to increase spending on new traps and mosquito staff.Photo: Isabella Escobedo