West Nile prevention comes with cost

Preventing the spread of the West Nile virus has come at a cost during this intense mosquito season.

According to Grand Forks Mosquito Control Supervisor Todd Hanson, in 2013, mosquito control has already spent approximately $900,000, which is $87,000 more than last year's total of $813,000.

"We have also had to take $50,000 out of a carryover fund," Hanson said. "And I estimate we will have to take out another $20,000 before the season is over."

Ground sprays, aerial sprays and general prevention procedures, such as larviciding, all contribute to the increased cost of mosquito prevention in 2013.

More spraying

Mosquito control will be conducting their 10th spray of the season Thursday night, as well as an aerial spray, their second of the season.

Spraying will begin around 8:30 p.m. and continue until midnight throughout Grand Forks and East Grand Forks.

Hanson said Thursday's aerial spray is intended to reach areas of Grand Forks and East Grand Forks that conventional spraying cannot.

"The aerial sprays will go over the English Coulee corridor as well areas along the river corridor," he said.

Aircraft will be flying low at approximately 150 to 300 feet.

Mosquito control trucks will be identified by a flashing yellow light and residents are advised to avoid walking or running through the aerosol cloud of insecticide let off by the trucks.

While aerial sprays are expensive to conduct, Hanson said larviciding costs the department the most dollars per year.

Larviciding is the process mosquito control uses to kill mosquito larvae in stagnant water by applying insecticides.

Hanson said there are thousands of sites in the Grand Forks area that are treated on a regular basis.

Identifying the virus

With three birds testing positive for the West Nile virus in 2013, along with ideal weather conditions for increased mosquito populations, Hanson said extra precautions have been necessary.

However, no more testing will be done on birds this season.

Hanson said thousands of culex tarsalis mosquitoes, the species most common for transmitting the West Nile virus, have been found in traps this summer.

"Things started out very wet and then got very warm this season, causing very high populations of mosquitoes that carry the West Nile virus," he said.

According to Hanson, the population of culex tarsalis mosquitoes increases throughout June and July, typically peaking in August.

"We would rather shift our resources somewhere more useful in preventing the spread," he said.

In 2012, three human cases of the West Nile virus were reported, and while no human cases have been found in 2013, weather conditions in 2012 were not as threatening as they have been this season.

"Every year we know that the virus is around," Hanson said. "It's only when the conditions are the way they are this year do we fear the amplification of the virus."

Hanson speculates the virus could have been carried to Grand Forks by migrating birds, but is unsure of an exact origin.

Call Ashlock at (701) 780-1137; (800) 477-6572, ext. 1137; or send email to aashlock@gfherald.com .