Conditions Right Now Are Perfect For Even More Mosquitoes

DENVER (CBS4) - Colorado's warm conditions are just right for a big increase in mosquitoes, and on Tuesday the first case of West Nile virus was reported in Colorado this season.

A Longmont woman reported that she first became sick on July 4. She was never hospitalized and her condition has improved. Still, it's prompting the city of Longmont to take precautions. They'll start spraying for mosquitoes Wednesday night.

That's only the beginning. Conditions in Colorado right now are perfect for even more mosquitoes to come out. That's because the insects thrive on all the moisture followed by the heat.

It's already happening in some areas. A pond in Commerce City was sampled for mosquito larva and nothing was found. But the real story is what's already being found in parts of Weld County. From a single trap there were thousands of adult mosquitoes.

"It's above what we would normally expect for this time of year," said Doc Weissmann, who runs the lab for Colorado Mosquito Control.

Blame the heavy monsoon rains and above-average snowmelt. The combination produced plenty of moisture so vital to the egg production of mosquitoes. It's being followed this week by a heat wave that's speeding up their life cycle.

"By next week we're probably going to see an even higher peak than we're seeing now," Weissmann said.

Weissmann's team keeps track of how many and what types are breeding right now. They worry about the mosquitoes that transmit West Vile virus. They're called culex tarsalis and have distinctive markings.

"It's got stripes on the joints of the legs," Weissmann said.

The big increase in culex and other types of mosquitoes is occurring in the irrigated farmland along the Front Range. But communities along waterways are also at risk. So chemical controls are being stepped up now to eliminate the larva before they become adults.

Experts say to use mosquito repellents with deet, wear protective clothing, and avoid being outdoors at dawn or dusk.