Mosquito control effort turns toward spraying

By Cherry Sokoloski
North Forty News

Mosquito spraying has begun in Larimer County in an effort to control the West Nile Virus, and the community of LaPorte is not exempt.

LaPorte is considered to have a fairly dense population, and mosquito traps have been set in the community. If Culex mosquito numbers start to rise, LaPorte could be added to the list of areas sprayed.

Traps have also been set in Livermore, Red Feather Lakes and Crystal Lakes, to see if Culex mosquitoes, which transmit the West Nile Virus, have migrated that far. None have been found in those areas to date. It is not anticipated that those communities would be sprayed, however.

Spraying began in and around Fort Collins on July 20 and will continue until mosquito numbers begin to decrease, probably sometime in September. Each "spray event" includes two sprays, three or four days apart, according to Lee Anne Kempton, environmental health specialist with the Larimer County Health Department. Spraying will be conducted as often as necessary in densely populated areas of the city and county, she said.

In Larimer County, there have been eight human cases of West Nile Virus so far this year, compared with only one by this time in 2003. "We're four to six weeks earlier this year," said Ann Watson of the health department.

Colorado Mosquito Control is carrying out the spraying for Fort Collins and Larimer County. The company is using a permethrin-based insecticide applied in a fine mist. Kempton described the application rate as "ultra-low volume" and said it should not pose a health hazard to people. "We wouldn't spray anything considered dangerous," she said. The insecticide is designed to kill only small insects and dissipates quickly, according to Watson. If people are concerned, she added, they are advised to close windows and stay inside during spraying periods.

In the north part of the county, the four initial spray areas are the Summit View area between Prospect Road and East Mulberry Street and three subdivisions east of Interstate 25. The subdivisions include Vista Bonita, Cloverleaf Mobile Home Park and Clydesdale Park. The Fort Collins spray areas extend from College Avenue to I-25 between East Mulberry and Drake, and from Timberline Road to I-25 between Horsetooth and Kechter Roads. Timnath was added to the spray list on July 26.

Areas were chosen because of high numbers of Culex mosquitoes, Watson said, and additional areas will be added as mosquito numbers rise. A total of 94 mosquito traps have been set in Larimer County.

Spraying is done from trucks and begins just before sundown, continuing until about 11:30 p.m. when temperatures drop.

Watson said the department has received complaints from residents on both sides of the spraying issue. Some object to spraying because of possible harmful effects on beneficial insects and human health; others are upset that their neighborhoods aren't being sprayed.

The spraying schedule and a map are on the county's web site at www.larimer.org/health; or, call 498-6797. E-mails will be sent to those who sign up for a subscription to the county's notification service. Go to the web site and click on West Nile Virus subscription service.

The county has budgeted $200,000 for spraying, on top of the previous $100,000 designated for education, testing and larvicide application. Fort Collins spends about $31,000 each time a spray event occurs, in addition to $6,000 for the reverse 911 notification of residents. The city plans to spend whatever is necessary to comply with health department recommendations.

Health officials continue to advocate use of mosquito repellants. Products with DEET have the longest protection time, but alternatives are available. According to health officials, Off! Deep Woods, with 23.8 percent DEET, will protect the user from mosquitoes for 302 minutes. In comparison, an application of Skin-So-Soft Bug Guard, with 0.1 percent citronella, will protect a person for 10 minutes.