Insect outbreak expected to be greater than last year's


Early summer flooding and warm weather are two factors contributing to one of the biggest insect outbreaks Moffat County Pest Manager Bruce Johnson has seen in Northwest Colorado.

A combination of mosquito hatchings, Mormon cricket migrations and grasshopper invasions has been keeping the entire department busy and has kept Johnson out in

the field for three straight


"I don't think I'll get a day off for another month," he said. He wasn't surprised, "I figured it was going to be this way this year."

His office has been flooded with calls from residents complaining about the above-average population of mosquitoes at the same time Johnson is combing the Maybell Ditch trying to control Mormon crickets before they get in and are transported to already-stressed croplands. He also is treating the above-average infestation of grasshoppers.

"We're getting daily complaints," he said. "We're spread out so thin, but we get to them as soon as we can."

Johnson said many of the complaints are directed at him personally, blaming him for the number of mosquitoes in the air.

Johnson has two of his crew of six seasonal workers helping him slow the spread of crickets and grasshoppers and the other four are fogging mosquitoes nightly.

"The boys are going as fast as they can," he said. "We're doing the very best we can with the money we have."

Hot weather early this month caused snow to melt in the high country, flooding the Yampa River. The flooding created pockets of water that can be the birthing place for up to 3,000 mosquitoes a week. Many of those puddles aren't reachable by pest management crewmembers.

He said he expects the situation to improve as the water level falls and those pockets dry out.

He's planned

Johnson is stepping up the county's mosquito-abatement efforts in the hope of curbing the spread of the disease locally.

He will treat about 20,000 acres between Craig and Maybell with larvicide -- irrigated hay fields and standing water where the bugs are bred. The county kills adults by fogging 20 to 30 hours a week and contracts for an aerial attack twice during the summer. The first aerial spraying is scheduled to occur at the end of June or the first week in July, but he might contract to spray along the river earlier, he said.

Ninety percent of the treatment is larvicide, Johnson said. Once mosquitoes reach adulthood, they are harder to kill.

In the water, the larvae are treated with bacteria that crystallize when larvae eat it and it blows out the sides of their gut.

A 40-pound bag costs more than $200.

"It's expensive stuff," Johnson said. "We switch chemicals every other year because mosquitoes have a tendency to become resistant."

The city has doubled its contribution to the mosquito-abatement fund and the county has established a contingency should Johnson feel more is needed.

"There are still going to be mosquitoes," he said. "It doesn't matter how much we spray."

Mormon crickets, which go untreated on federal land because there is no treatment program established, are migrating across an into Northwest Colorado. Right now, the biggest patch is on Colorado Highway 318 at the edge of Maybell and crossing the state line from Utah.

"We've got lots of heavy bands," Johnson said. "It's building. The BLM and other federal agencies don't have an abatement program. Basically we're it and we can't do anything until they leave federal land."

He judges this year's infestation as "a lot worse" than last year's, which some ranches said was the worst infestation they had seen in 20 years.

He kills them using bait, which is effective, but not 100 percent effective.

The crickets will eat just about anything green, which will rob both farm animals and wildlife of graze.

"When they're traveling its OK, but when they stop, they really eat," Johnson said.

The crickets are killed using an insecticide-treated wheat bran called carboral. It is distributed at five to 10 pounds per acre, depending on the degree of infestation. And, because Mormon crickets are cannibalistic, a fatal dose to one has the potential to kill three.

The BLM, Johnson said, is considering creating a pest management program next year.

Johnson is working to keep the crickets out of crops, which he said is the department's priority.

Last year, Moffat County didn't see the kind of grasshopper infestation that was reported in Routt County, but it didn't have pockets of the insects.

This year is expected to be worse.

Johnson has counted areas in Morapos Creek and Price Creek with more than 100 grasshoppers per square yard and a few with up to 200 grasshoppers per square yard. The largest infestation has been found east of Craig along the Moffat County line.

Johnson said it's the worst infestation he's ever seen.

The hoppers are treated by a growth-inhibiting insecticide commonly known as Dimilin, but at $200 a gallon, it's an expensive killer. Experts say Dimilin is considered environmentally sound because of its minimal effects on other creatures.

Johnson plans to treat the grasshoppers from the air if he can get permission from landowners.

Routt County also is experiencing problems.

The insects are beginning to descend on fields, and experts say this year's problem could be worse than last year, when swarms of grasshoppers devastated lawns, crops and pasture land.

Routt County residents have counted as many as 360 of the insects in one square yard of ground. That's nine times the threshold considered to be infestation, which would justify the use of insecticides, Colorado State University Cooperative Extension Agent C.J. Mucklow said.

''I said to myself, 'I'm not going through another summer like that,''' said Mary Kay Monger, whose ranch was besieged last summer. ''I'll do whatever I can to get rid of them.''

The tiny grasshoppers showing up now are the offspring of last year's swarm, and the warm spring has helped them thrive, said Carl Bock, a professor of grassland ecology at the University of Colorado at Boulder.

Mucklow also is using Dimilin to battle the bugs.

Homeowner John Worden said the infestation was so bad his dogs wouldn't go outside and his 40 acres were eaten ''to bare dirt.'' He said his two boys took turns shooting the grasshoppers with BB guns.

''The only thing they didn't eat was the weeds,'' Worden said. ''If we could educate them to eat the weeds instead, it would be great.''

Worden is among the Routt County residents who have asked the extension service to spray their land.

''I don't want to claim or pretend that we're going to stop this infestation,'' Mucklow said. ''This is a natural thing that is too big for us to handle alone. Mother Nature should help with cool weather. One way or another, it should eventually clear up on its own.''

Controlling the three insects is keeping Moffat County's Pest Management Department hopping.

"We're bouncing from place to place," Johnston said. "We just have a mess out there. We've never had a year like this."

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