West Nile meets Batman

Flathead mosquito control, one bug at a time



Last summer, Montana reported 228 cases of West Nile Virus and the virus-related deaths of four senior citizens. West Nile, which can deteriorate the central nervous system, was found primarily in eastern and central Montana, although a few cases were reported in Lake and Glacier counties. According to the Centers for Disease Control (CDC), one in 150 people infected with the virus will become ill, with symptoms ranging from fever and nausea to paralysis and permanent brain damage. Flathead County didn’t report any West Nile cases last year, but because the disease seems to be spreading from east to west, last year’s lack isn’t stopping the Flathead County commissioners from thinking ahead, particularly when 34 percent of the state’s cases last year resulted in neurological problems.

“We don’t want to wait until we’re in an emergency to deal with this,” says County Commissioner Gary Hall.

Flathead County Health Officer Joe Russell spoke to the commissioners at a June 8 meeting, saying, “The reason you’re all here is because we realize it’s not if, but when.”

A typical response to the virus, which is mainly carried by mosquitoes and transferred by bites, has been pesticides.

“I’ve been getting a lot of calls from people who say, ‘please spray,’” Hall says.

Currently, the county uses larvacide, a chemical that kills mosquito larvae in breeding grounds. Since 2000, the county has maintained a ban on another chemical pesticide, Malathion, which several researchers have concluded may cause death, birth defects or intestinal disorders, among other problems, in children.

At the June 8 meeting, Russell suggested that the commissioners might want to consider rescinding the Malathion ban to deal with the virus, or consider the use of another, more expensive chemical spray, Scourge, which has received less negative public comment, although the spray contains the synergist piperonyl butoxide, which the Environmental Protection Agency lists as a Class C carcinogen. The spray is distributed via airplane, and the county could notify those who are allergic or sensitive to the chemicals to move away on spraying days, says Jed Fisher, Flathead County director of weeds, parks and recreation and building maintenance.

Even if the county can find a chemical spray with side-effects or possible side-effects that are acceptable to the public, however, health officials and county commissioners expressed concern that further opposition would be likely to come from area organic farmers, who must be certified and guarantee customers that their crops are chemical-free.

Yet there is a method to help control the mosquito population without aerial sprays, according to Lakeside resident Ed Mikulecky, who suggests the county turn to Mother Nature for its solution: specifically, to bats.

Mikulecky, a brush-clearer who builds bat houses on the side, notes that a single brown bat can consume over 600 insects in an hour, or 4,000 in a single night. Scientific research into West Nile transmission concludes that bats, unlike mosquitoes, cannot directly transmit the virus to humans.

“The spray program is killing the bats and making the children sick,” Mikulecky says. “Maybe the virus is something we’ve brought on ourselves because we’re killing all the bats.”

In 2003, the Montana Natural Heritage Program, which tracks plant and animal populations within the state, listed four of Montana’s 15 bat-types as “species of special concern,” while further study was needed on three other species. Both the spotted bat and the pallid bat received the lowest ranking a species can get without being extinct, but other species showed gains since a 1995 study.

Mikulecky doesn’t propose bats as a cure-all, and says there’s a role for pesticides to play, but argues that their role should be complemented by bat habitat protection and governmental encouragement for bat houses. Such a community initiative, he says, would be much less expensive than conducting aerial spraying, would come without the health concerns associated with pesticides and could reduce the West Nile threat in the long run.

The Flathead has been without a county agricultural agent to advise on how to deal with such a threat for the past 12 years, according to Karol Sommerfield in the County Extension Office. A new agent is expected to begin in July, but in the meantime, one step that anyone can take, Mikulecky says, is building a bat house on one’s property.

“It’s just a framed box, preferably red cedar,” says Mikulecky. “It could take a couple of years for the bats to adopt it as a nest.”

While some property owners might balk at attracting bats, Mikulecky says the alternative—more chemical spraying—is ultimately less attractive than the winged mammals.

Mikulecky says he developed his natural insect-control philosophy as a farmer. He used pesticides originally, but eventually turned to birds of prey to control a grasshopper population.

“And I think my crops were better than the neighbors’” who stuck with pesticides, he says.

Although he proposed the use of Scourge at the commissioner’s meeting, Jed Fisher says that a bat initiative could be “an excellent way to go.”

Currently, Fisher says his multiple roles don’t allow him to dedicate the time to mosquito control he thinks the county requires, and he points to Colorado communities using the bat technique as precedent. One such community is Parker, Colo.

Parker Community Affairs Coordinator Kena Peterson says that the local public works department has put up a number of bat houses around town after a “handful” of West Nile cases popped up last year. Parker has opted against spraying due to environmental concerns, Peterson says. Instead, Parker supplements its mosquito attack with natural bacteria tablets placed in still bodies of water.

“It’ll take a few years before we find out” if the bat houses are effective, Peterson says.

With such a timetable, Parker’s bat houses are a long-term project, but one that Mikulecky thinks should be duplicated now, before the first case of West Nile arrives in the Flathead.


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