Michigan Residents Ready for Gypsy Moth Combat

DETROIT, Mich. - Rochester Hills resident Dawn Bovensiep can't wait for the pesticide helicopter to fly over her house this month.

She hopes the mist coming from the chopper kills most of the hairy, black gypsy moth caterpillars feasting on the oak tree leaves in her yard.

She remembers last summer, when the caterpillars became inch-wide brown-and-white moths and swarmed her yard and her sister's next door on Alida Avenue.

"The end of July through August was just horrible -- and that's the best time to be outside," said Bovensiep, 28. "You couldn't let the dog in without having a flyswatter in your hand."

Bovensiep and 2,700 other property owners in Oakland County may have relief this summer.

The Oakland County office of the Michigan State University Extension notified them that their land and trees will be sprayed with Bacillus thuringiensis, also known as Bt, a bacteria eaten by and fatal to gypsy moth caterpillars. Spraying is expected to start Saturday, weather permitting.

The pesticide does not affect humans, animals or other insects and won't hurt paint finishes, Oakland County officials wrote in an April 16 letter sent to affected residents.

The helicopter will spray 1,770 acres along the eastern end of Oakland County, in Rochester Hills, Auburn Hills and Oakland, Addison, Oxford, Orion and Waterford townships.

Spraying must be done shortly after the caterpillars have hatched but before they get too big to be affected by the bacteria they eat. The caterpillars' growth, leafing of trees, humidity, and weather conditions all play a part.

Those with gypsy moth problems can thank a French naturalist eager to create an American silk industry in the late 1800s. He brought the caterpillars to Massachusetts in 1869, saidCarol Lenchek, environmental programs coordinator for Oakland County's Michigan State University Extension office. They've been a problem ever since.

Their fuzzy, buff-colored egg masses, the size of a quarter, stick to the bottom and backs of anything, including swing sets, lawn furniture and the inner side of tree bark.Each egg mass can produce between 500 and 1,000 caterpillars, Lenchek said.

Thankfully they aren't as destructive as Michigan's other high-profile pest, the emerald ash borer. Ash borers kill ash trees; gypsy moths defoliate oak trees and defecate a lot, said Thomas Fink, a forestry ranger with the City of Rochester Hills.

"Mainly, it's a nuisance problem," Fink said.

Bovensiep remembers hearing droppings like rain on leaves last year: tiny gypsy moth feces showering from the trees.

"There's nothing you can do, except no picnics outside," Bovensiep said. "They're pretty bad."

Natural predators and the moth's cyclical nature have kept their numbers down in Oakland County since 2001, the last time the county sprayed. But local forestry workers continually monitor gypsy moth populations.

Across the county, the number of caterpillars found in the traps last year showed an increase. And, cost-wise, it's most economical to spray at least around 2,000 affected acres, Lenchek said.

Rochester Hills, home to most of the affected areas, is paying the $42.50-per-acre cost for the spraying by Helicopter Applicators of Gettysburg, Pa.

After the spraying, affected caterpillars should drop to the ground and disintegrate.

For more information on gypsy moths or to report a potential problem, call Oakland County's Michigan State University Extension Office at 248- 858-0902 anytime.