RI’s DEM explains why it isn’t spraying against gypsy moths


GLOCESTER, R.I. (WPRI) — Rhode Island is under a full-scale assault by gypsy moth caterpillars. The insects deforest trees and can cause people to break out in rashes. So, one of the biggest questions into the Eyewitness Newsroom about the outbreak – why isn’t the Rhode Island Department of Environmental Management spraying?

Eyewitness News went to the source for answers – sitting down with Paul Ricard, the Forest Health Program Coordinator for the DEM’s forestry division.

Ricard said the DEM came to the decision not to employ aerial spraying of insecticides after forming a committee to decide how best to handle the recent outbreak.

In total, 1.3 trillion gypsy moth caterpillars are expected to hatch this year, said  “The gypsy moth caterpillars are hatching. Most of them, as a matter of fact, have already hatched,” he said Thursday.

Last year, the caterpillars defoliated 226,000 acres of trees in Rhode Island and similar results are expected this year.

So, why not spray?

“It’s practically impossible to spray 400,000 acres of forest land,” said Ricard. “Even if we did, we couldn’t assure that the gypsy moth infestation would stop.”

And what would the cost be? Hundreds of thousands of dollars?

“Oh, no,” said Ricard. “We’re talking hundreds of millions of dollars.”

The caterpillars have various stages. They can spin threads of silk in their travels when they’re basic tube shapes. Later in their lives, they sprout silky hairs. To the curious — young and old — they may appear soft and enticing to touch. Instead, the hair includes chemicals that can lead to a rash in humans.

When they get onto trees or outdoor structures — like park or school play structures — it’s easy for the caterpillars to transfer onto human bodies. Though that puts them closer to the danger of giving humans rashes (they can also drop from aloft onto humans), they are not on the attack, and are avoidable, said Ricard. “That’s a nuisance, but it’s not a public health hazard for a majority of people.”

Ricard recommends homeowners take up sprays themselves to their foliage. Your local garden center or hardware store is likely to offer pesticides with BTK (“bacillus thuringiensis kurstaki”) or “spinocid” as their active ingredients.