It's open season on irritating caterpillars

Other resources on the browntail moth

By Andrew Garber
Staff Writer
©Copyright 1998 Guy Gannett Communications

Roy Jackson has itchy red bumps in an armpit and on an elbow. He expects to have a lot more places to scratch soon as the caterpillar season on Great Chebeague Island progresses.

''It's a wicked itch,'' he says. ''Just like poison ivy.''

Jackson, and others like him who react to hairs shed by the bugs, hope an aerial attack against browntail moth caterpillars will help keep rashes to a minimum this summer.

Spraying of the moths is expected to begin today in Falmouth and continue through several other communities, including Yarmouth, Cumberland Foreside and Chebeague Island, during the next few days.

In all, about 3,000 acres will be sprayed from the air with Dimilin, said Dick Bradbury, an entomologist with the state forest service. Much of the aerial spraying will occur between Route 88 and the water.

Another 1,500 to 3,000 acres will be sprayed on the ground using a variety of compounds, he said. That spraying is already under way.

Costs of ground and air attacks could reach $150,000 or more, Bradbury said. Communities and individual land owners will pay the bill, he said.

Dimilin is a petroleum product that has caused controversy because it can damage the shells of lobsters, clams and other shellfish. Spraying is prohibited within 100 feet of the shoreline.

Some people have requested that their land not be sprayed by air. In Yarmouth, for example, four people have requested that their property not be sprayed, said Marcia Noyes, the town's community services director.

But that number is down from the eight people who originally declined, she said. Four of them changed their minds.

Bradbury said Dimilin does not pose a threat to people, but he advised folks to go indoors if they see the spray plane coming. Bradbury also said it would be best to keep children inside until the grass and foliage are dry.

The spraying generally takes place between 5 a.m. and 10 a.m., before the winds pick up, he said.

Dimilin kills the caterpillars by interfering with the biological processes that harden their shells so they can molt, Bradbury said. Dimilin prevents the shells from hardening. Eventually, so much pressure builds up inside the caterpillars that they burst.

''It's kind of gruesome,'' Bradbury said. And effective, with kill rates up to 99 percent, he said.

The spraying kills the caterpillars before they develop the hairs that cause rashes and respiratory problems for people.

The tiny hairs pose a hazard when they become airborne and are inhaled or land on people's skin. The hairs carry toxins, which probably help protect them from being eaten by birds, Bradbury said.

Jackson said he does a lot of outdoor work on the island, cutting trees and clearing land. Invariably he begins itching when working in the trees.

The hairs cause ''red welts that stick up quite a bit,'' said Jackson, who uses a variety of creams to stop the itching and has even had to use antibiotics.

Jackson advised people who are affected by the caterpillar hairs to take a shower as soon as the itching starts and to put on clean clothes.

Even though the spray campaign is expected to be successful, Bradbury expects the caterpillars to be back next year in even larger numbers.

That's because only a small portion of 50,000 acres infested statewide is being sprayed. Plus, each female caterpillar can produce 400 eggs.

''We're strictly trying to protect people with the spray,'' Bradbury said. ''If you look at an insect that can produce 400 offspring, you can't even consider eradication.''

The caterpillar infestation has been steadily marching up the coast over the past several years, he said. Infestations of the caterpillar generally run in 10-year cycles, Bradbury said. This cycle started around 1991.

If the pattern holds true, the caterpillar population should start dropping within three to four years, he said.

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Other resources for information on the browntail moth

• Combating the Browntail Moth is an account of the 1996 spraying effort on the Casco Bay islands. Includes information about the moths and their effects. Includes a text file of moth precautions.
• The Maine Office of Geographic Information Systems has a map of the 1994 moth infestation.
• Fourth graders at Hawthorne School in Brunswick have posted an informative page on the moths.
• The Cliff Island Page has a report of this year's Browntail Tally.
• The University of Southern Maine's Steve Puleo has posted an opinion piece he wrote for the Press Herald, arguing against aerial spraying.

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