Flood water creating mosquito problem? Canyon County discovers massive number of larvae

Canyon County discovers massive number of mosquito larvae in flood water. (KBOI Photo)

Flooding is creating a new problem for Canyon County. Leaders are now concerned about massive numbers of mosquito larvae.

Normally around this time of the year, the county starts trying to kill mosquito larvae if they find one larva in a cup-sized sample of flood water. But because of the increased flooding this year, in some spots they're finding hundreds of larvae in one sample.

"Within the last week or two, within the last week really, is when we started finding massive amounts of mosquito larvae in some of the areas that are flooded where the water is shallow and the water temperatures warmed up enough for these mosquito to hatch out," said Ed Burnett, director of the Canyon County Mosquito Abatement District.

Burnett says they usually see these type of mosquitoes every year, but nothing like the number they're finding now. These larvae are called inland floodwater mosquitoes. Usually floodwater doesn't reach many of the eggs so they can't hatch, but this year is different.

"They hatch out in areas that are flooded, the eggs can stay viable for up to 7, roughly around 7 years, in the soil they'll stay there and then when we get a flooding like this, when there's record flooding, that triggers the hatching of this particular species," Burnett said.

Burnett warns that these larvae will become flying mosquitoes when the weather heats up and they travel in big swarms. But these aren't disease carrying mosquitoes.

"The bad thing is they'll start hatching out in very very large numbers and they're ferocious biters and they'll even fly around in the day time, the good thing is they aren't a disease carrier they're not like our West Nile Virus or anything like that," Burnett said.

The county is trying to aggressively kill the larvae before the weather warms up. They use a bacteria that Burnett says is not harmful to humans, fish or animals.

"We've treated 400 acres so far, over 200 acres of deer flat wildlife refuge, where these mosquitoes are coming from right now, and we have another 250 acres schedule for the Boise river south of Middleton," Burnett said.

The Boise River treatment starts Wednesday. The Mosquito Abatement District will be using a low flying plane to drop the bacteria.

When the weather heats up, Burnett advises everyone to make sure to use mosquito repellent when around water.