Gypsy Moth Caterpillar Fungus Slow to Make an Impact: State Entomologist

This wet spring was supposed to help mitigate the massive gypsy moth caterpillar problem in the southeastern part of the state. The rain triggers a fungus that kills the caterpillars, but now experts are saying it’s working slower than expected. 

This year’s gypsy moth caterpillar outbreak has been “pretty extensive and severe,” State Entomologist Kirby Stafford III said in an email to NBC Connecticut. While the rains have been ideal for the gypsy moth caterpillar-killing fungus, it’s been slow to take effect. 

But he does have spotty reports of caterpillars dying from that fungus. 

So Tim Day’s family, who lives in Gales Ferry, took matters into their own hands. 

“They sprayed insecticide on the trees two days ago and then basically thousands of gypsy moth caterpillars fell out of the trees,” Day said. 

Beverly Joyce, of Ledyard, has seen her trees dying. She said her husband has used a leaf blower to try and get rid of the caterpillars – and even got a rash from them. 

“It’s been bad. Our trees have been chewed. There’s nothing left of them,” Joyce said. 

It’s not ideal for someone who loves to be under a shady tree in the summer. 

“You hide inside when you can,” Joyce added. 

Trees are severely stressed due to the drought and the caterpillars, making them less likely to recover, according to Stafford. Some have already died. 

But he said there’s still a chance the fungus will kill more of the older caterpillars as they move around. 

Joyce is hoping her method will kill them, too. 

“Bug zapper. Once they turn to the moth mode, we’ll use a bug zapper and hopefully get rid of them,” she said. 

As for next year’s gypsy moth caterpillar outlook, Stafford said he and his team will look at what the adult moth population looks like and conduct an egg mass survey again in winter. 

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