Gypsy moths moving closer to oak groves

COLUMBUS – Gypsy moths are making their way south and west in Ohio; inching closer to the state’s largest area of oak trees, the moths’ favorite snack.

This year 43 of Ohio’s 88 counties are under quarantine, which means they are infested and all nursery stock and timber must be inspected before exported out of those counties. In 2000, Licking and Coshocton counties were the hardest hit, and Dan Balser, forest health specialist with the Ohio Department of Natural Resources’ Division of Forestry, says this year’s defoliation surveys will likely show the same results.

“Once the moths move south of Columbus, they will find Ohio’s largest groves of oak trees. They really could have an unlimited food service,” said Balser. “Figuring out how to control them will be a problem.”

Balser and Deborah Abbott, Ohio Department of Agriculture spokesman, say Ohio’s gypsy moth problem is as dire as it was 10 years ago, but the moths have moved around, creating new problems.

Moving target.

“If you would have asked someone in Ashtabula County about gypsy moths 10 years ago, they would have told you they have never experienced something so terrible, but if you would have asked someone in Licking County the same question, they wouldn’t know what you were talking about,” said Balser.

“Now, the people in Licking County would tell you it’s like nothing else they’ve experienced and Ashtabula County will tell you it’s not a problem.”

“I’m not sure if they would tell you that because the problem has gotten better or because they’re just used to the moths in Ashtabula County now,” said Balser.

Gypsy moths advanced into Ohio from Pennsylvania over the last decade. In its caterpillar stage, it feeds on the leaves of trees and shrubs.

Last year, ODA’s Plant Pest Control Section launched the largest suppression treatment project in the program’s history, treating more than 71,000 acres in 14 counties.

Defoliation was limited to nearly 24,000 acres of trees – half the number of acres as in 1999 – and was found in different locations than previous years.


The suppression treatment uses pheromones, chemicals produced by insects to communicate, to alter the behavior of the adult moth. The pheromone is incorporated into plastic laminated flakes that are mixed with a sticking agent and released from an airplane.

Once the flakes are released, they saturate the air in the area with the pheromone for 2 to 3 months, disrupting the communication between the female and male gypsy moth.

The release is timed to correspond with the male gypsy moth’s flight, preventing him from finding the flightless female and mating.

Abbott said ODA just completed aerial suppression treatments in 44,250 acres in southern and western Ohio, but no results were available. Defoliation surveys will be completed within the next few weeks.

Steve Miller, director of Coshocton Park Districts, says suppression treatments made a big difference at the parks this year.

“Last year, there were about 8 acres infested with the moths, but we haven’t seen nearly as many this year,” said Miller. “We continue to monitor our trees closely, and have killed many egg masses and caterpillars, but we still have not seen the sheer numbers that were here last year.”

Big budget.

Landowners should expect more aid from ODA in 2002-03, because the state budget for gypsy moth eradication was increased to $1.25 million.

“There is still a huge population of gypsy moths here in Ohio. No one is sure if Ohio will ever be rid of them, but by increasing suppression treatments, slow-the-spread treatments and defoliation surveys, we can do a better job protecting Ohio from the spread of gypsy moths,” said Abbott.


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