Skeeter slayers will take prisoners

Published 12:00 am Tuesday, May 21, 2002

By JAYSON JACOBY

Of the Baker City Herald

Jim Lunders is paid to kill mosquitoes, but this year he will trap some of the pesky insects and keep them alive.

For a few days, anyway.

Lunders manages the 200,000-acre Baker Valley Vector Control District, which encompasses most of Baker, Bowen and Keating valleys.

He secured a $6,000 grant from the federal Centers for Disease Control and Prevention and the Oregon Health Division to trap adult mosquitoes this year and mail them alive to a state lab in Portland.

Experts there will test the skeeters for nasty viruses such as West Nile and several types of encephalitis, Lunders said.

West Nile, a potentially fatal disease, made headlines in 1999 when it infected dozens of birds and several people on the East Coast.

Although the virus has not spread to Oregon, scientists predict it will arrive here within the next few years, Lunders said.

He will deploy 18 traps across the district this year.

Here’s how the $100 devices work:

Workers dump dry ice into a black, one-gallon plastic bucket (it looks like a paint container). Dry ice, which is solidified carbon dioxide, attracts mosquitoes, Lunders said.

Mosquitoes, he said, can smell carbon dioxide. This is why it’s impossible to hide from mosquitoes the plume of carbon dioxide you spew out every time you exhale lures them as a lantern attracts moths.

Hanging below the bucket of dry ice is a simple battery-powered fan. The fan sucks mosquitoes into a mesh trap.

Lunders said he intends to trap about once a week. He’ll set them up in the evening, then collect them the next morning to be sure the mosquitoes are still alive.

Back in his office at the Baker City Municipal Airport, Lunders will separate the trapped skeeters by species and gender.

Then he will pack 20 to 50 female skeeters in dry ice (males he can dispose of they don’t bite), seal them in a package and mail them to the lab.

The mosquitoes need to be preserved in dry ice so scientists can test them for diseases, said Dr. Emilio DeBess, Oregon’s public health veterinarian.

DeBess said nine mosquito-control districts in Oregon are trapping the insects for testing.

Besides tracking harmful viruses, the trapping program will help Lunders gauge mosquito populations, and thus decide when it’s necessary to spray chemicals to kill them.

The traditional method is the dreaded andquot;landing counts.andquot;

andquot;Basically you stand there and get bit,andquot; Lunders said, counting how many mosquitoes land on you every minute.

Landing counts, besides being uncomfortable for everyone but the mosquitoes and the sellers of calamine lotion, also are imprecise, Lunders said, because some people are more attractive to female mosquitoes than others.

Overall strategy remains constant

Other than the traps, Lunders said his anti-mosquito strategy will be similar to last year’s.

The drought, which seems to have regained its grip on Eastern Oregon, simplifies the job, he said.

andquot;If there’s no water it helps me a bunch,andquot; Lunders said. andquot;It’s not so good for everybody else.andquot;

Because water for flood irrigation was in short supply last year, fewer acres in the mosquito control district were submerged than normal, Lunders said.

And without standing water, the floodwater mosquitoes that predominate in Baker County weren’t able to mature from eggs to adults, he said.

Lunders said he used half as much pesticide as he expected last year.

But mosquitoes always are capable of staging a comeback.

Their eggs can remain in the ground for years, he said, needing only water to hatch.

andquot;There’s a pretty big reservoir of eggs sitting there,andquot; Lunders said. andquot;It’s like a built-in mechanism for the species to perpetuate itself.andquot;

Water temperature is crucial, too.

Right now standing water around the district is chilly, and the lower the temperature the slower the cold-blooded mosquitoes mature, Lunders said.

And that’s good news for mosquito killers, because it means the insects are vulnerable to pesticides longer.

Lunders’ main weapon is Bti, a naturally occurring bacteria available in both granular and liquid forms.

Bti kills mosquito larvae in three of the four stages of maturity between egg and adult, he said.

Now, with the water still cold, those three stages may take a week or so to complete.

But during the summer, when shallow water in irrigated fields warms fast, the transition from egg to biting adult might take just four days, Lunders said.

Be prepared

He will be better prepared to deal with outbreaks this year.

Lunders has hired three full-time assistants, one more than a year ago.

They will work for the duration of the mosquito season, which usually continues through summer.

Lunders is the only year-round employee for the district, which receives $280,000 per year from a property tax levy. District residents voted two years ago to double the former $140,000 levy.

District workers apply Bti from ATV and backpack sprayers.

Surveillance, though, is the key tactic, Lunders said.

He spends dozens of hours searching for mosquito breeding areas. Thousands of times each season he dips a hand-held net into standing water, looking for larvae.

By mapping breeding grounds, Lunders avoids wasting Bti by spreading it in places where no larvae live.

Some areas are too large to treat from the ground, so the district hires a helicopter to spray Bti.

One such area is at the north end of Baker Valley, north of Chandler Lane and between U.S. Highway 30 and Interstate 84.

Lunders relies on Bti, which kills mosquito larvae but not adults, for an obvious reason: dead larvae never become adults, capable of ruining baseball games and barbecues.

But it’s impossible to kill every larva.

andquot;There’s trillions of mosquitoes out there, so even if you get 90 percent kill (with Bti) there’s still billions,andquot; Lunders said.

So his arsenal also includes pesticides that kill adult mosquitoes.

When he needs to cover large rural areas he hires a helicopter to spray malathion.

For smaller areas outside cities, Lunders can spray pyrenone, which is made from chrysanthemums, from a cold aerosol fogger mounted in the bed of a pickup truck.

Inside Baker City and Haines Lunders fills the fogger with a synthetic version of pyrenone.

He said he can’t spray natural pyrenone outside cities because the state hasn’t approved its use on croplands.

For all his expertise, Lunders acknowledges he can’t track every squadron of skeeters.

He often relies on reports from residents who live, literally, on the front lines.

If mosquitoes have banished you to the indoors, you can call Lunders at 523-1151. If he’s out (which is common; you can’t kill mosquitoes from an office), leave a message.

andquot;It’s a lot easier if we all work together on this thing,andquot; he said. andquot;We’ll do a better job that way.andquot;

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