The Bolingbrook Park District and Woodridge Park District are taking different approaches to treating a recent infestation of gypsy moths at local parks.

Woodridge Park District crews were in Castaldo Park last week brushing caterpillars and pupae from the trunks of oak trees with push brooms, crushing them once they were on the ground.

“We also will treat the infestation next spring with a spray, but for now we have heard it can help to eliminate as many caterpillars as you can. So we were trying to get as many off the trees in Castaldo Park as possible,” said Don Ritter, deputy director of the Woodridge Park District.

“Whatever we can remove now will put us ahead next spring, any reduction is beneficial,” Ritter said.

Bolingbrook Park District officials are preparing to treat oak trees along the DuPage River Greenway by contracting with a firm that will apply an oily, soybean-based substance on eggs next spring in an attempt to eradicate the pests.

“At this point there is nothing we can do, so we will make our plans now or early next spring,” said Alice Eastman, superintendent of natural resources for the Bolingbrook Park District.

If the first application fails, Eastman said the next step will involve using a product called B.t.k. or Bacillus thuringiensis kurstaki, to kill the eggs.

“B.t.k. penetrates the caterpillars and infects them with a parasite that kills them,” said Eastman.

Ritter said the Woodridge Park District also will rely on B.t.k. next spring.

The two park districts agree the last resort would be to spray a “non-targeted” insecticide, which kills gypsy moths, but also other species of moths and butterflies.

“We really don’t want to take a chance in eradicating other species like Monarch butterflies,” Eastman said.

Eastman said the Illinois Department of Agriculture has set moth traps along portions of the Greenway to determine if a more aggressive program funded by the department is necessary.

“We should know later this year if IDA will provide some relief next year. Any help we can get, we will take,” Eastman said.

Gypsy moth caterpillars feed on leaves, and are particularly fond of oak trees, said Ritter.

“They really took down a lot of leaves at Castaldo Park,” Ritter said. On one side of the park the trees are still leafy, the other end it looks like The Wicked Forest,” Ritter said.

“If you go there and listen real close, sometimes at night you can hear them chewing the leaves. It is eerie,” Ritter said.