Agencies send forces to swat mosquitoes
5/16/2004Face it, folks. When it comes to mosquitoes, we're kind of wimpy.
Why, in the old days, we got bit and we liked it.
OK, maybe we didn't like it. But information collected by the Toledo Area Sanitary District - which sprays for mosquitoes in Lucas County - shows the number of mosquitoes swarming around was often far higher in years past.
"People tolerate a lot less today," said Lee Mitchell, a biologist for the district. "In the past, we had some gigantic mosquito years. Some of the numbers from the 1970s and 1980s are mind-boggling."
District employees have collected mosquito samples for some time, and it shows during the 1970s and 1980s often five or six times as many mosquitoes were collected compared to recent years.
There may be fewer mosquitoes buzzing around, but with the emergence of West Nile virus in Ohio in 2001, mosquito control officials have not been taking any chances. The virus, which is transmitted to humans by mosquitoes who bite infected birds, is rarely serious, but in some cases can cause fever, swelling in the brain, or death.
Last year, district officials sprayed a record amount of insecticide, and Mr. Mitchell expects about the same amount to be sprayed this summer.
Mosquito-control crews in Lucas County expect to start daytime spraying tomorrow, and start the more intensive night-time spraying around June 1.
Lucas County, which has sprayed for mosquitoes since 1946, is the only county in northwest Ohio or southeast Michigan with a countywide mosquito control program. However, some area cities have their own mosquito-control efforts, and a few have been beefed up in recent years.
Officials in Defiance, Perrysburg, Wauseon, and Sandusky all reported they intend to start spraying late this month, or in early June.
Like Ohio, mosquito control in Michigan is left up to individual townships or cities. Many have no active control programs, though some, including Bedford Township, do.
"We know it works," said Mike Pisarsky, superintendent of horticultural services for Sandusky. His city started mosquito spraying in 2002 because of fears
about West Nile virus. A Sandusky man died that year from West Nile virus.
"We'd rather not do so much spraying, but we have concerns about the virus," Mr. Mitchell said.
The Toledo Area Sanitary District spends $2.3 million annually, funded by property taxes, on mosquito control. Last year, the district sprayed 4,698 gallons of insecticide in Lucas County compared to an average of 3,000 gallons in the late 1990s before West Nile showed up. Mosquito traps last year collected 5,000 mosquitoes at 14 sites scattered throughout the county. In the 1970s and 1980s, and as recently as 1996, the number collected exceeded 20,000 some years.
West Nile's impact in Ohio and Michigan last year was relatively minor. There were 108 human cases in Ohio, eight of which were fatalities. In Michigan, there were 19 cases, two of which were fatal.
In 2002, Michigan and Ohio were the second and third-hardest hit states in the country. Then, the virus infected 441 Ohioans, killing 31. In Michigan, there were 614 cases and 51 deaths.
It's anyone's guess what will happen this year, according to Dr. Amy Bode, a West Nile expert at the federal Centers for Disease Control and Prevention in Atlanta.
"It's really hard to predict," she said.
Weather is probably a factor, but she said experts are not sure how much it influences the virus' spread. Some have suggested that dry years are actually better for the spread of the virus because the mosquito species that usually transmit the virus might do better in dry weather.
Dr. Bode said that appeared to happen last year in the hardest-hit state of Colorado, which had a third of the nation's cases. She is based at the CDC's division of vector borne diseases in Fort Collins, Colo. She said Colorado had a wet spring and dry summer last year. Despite the dry weather, there were 2,947 cases and 61 deaths in Colorado in 2003.
"Remember, mosquitoes don't need much when it comes to places to breed," she said. "What seems ungodly dry to us, they say, 'Hey, look at this little puddle, this is great to lay eggs in.'●"
That's why Dr. Bode and other mosquito-control experts stress that spraying for mosquitoes is only part of the solution. Control efforts should include larviciding, which is the use of agents to kill larvae in standing water. Lucas County, as well as most area cities with control efforts, have active larviciding programs. Some, such as Wood County, provide free larvicide pellets to residents.
Bedford Township conducts spraying throughout the township, but also provides larvicide to residents for use around ponds or other standing water that provide critical breeding habitats for mosquitoes.
Old tires, birdbaths, wading pools; pretty much any puddle or container that holds standing water is a potential breeding site. Abandoned swimming pools are a frequent problem.
Mr. Mitchell said the public can report instances of standing water on a property.
Complaints can be directed to the local health department, which can investigate to see if a public health nuisance exists. In Lucas County, such situations can also be reported to the sanitary district.
The rising popularity of decorative ponds in landscaping has also increased the possibility of creating breeding grounds for mosquitoes. Mr. Mitchell said one thing owners of these pools can do is put some "mosquito fish" in them.
These are tiny fish that devour mosquito larvae.
The district gives away these fish free to Lucas County homeowners; 1,200 homeowners have them at last count.
Finally, health and mosquito experts say it's OK to be a wimp, at least when it comes to mosquitoes.
The use of mosquito repellent, as well as making sure open windows or doors are covered with screens, is advised by no less an authority than the CDC, as well as local and state health officials.
"When a person is unlucky enough to get bit, they're at risk," Dr. Bode said.
"Mosquito-control programs and personal protection are the best weapons."
Contact Luke Shockman at:
lshockman@theblade.com
or 419-724-6084.