Is a Fort Worth caterpillar infestation killing trees? Here’s what an expert told us.

The trees in Fort Worth survived a hot and dry summer, but are now under attack from creepy crawlies.

It was a long blistering summer for the trees. The last times Fort Worth saw heat this intense was back in 1980 and 2011. Rain did eventually come to knock off a 67-day dry spell, and in the process made August one of the wettest on record.

A dry summer followed by intense rains and back to yet warmer temperatures last week could lead to caterpillar infestations, said Craig Fox, forester at the city of Fort Worth.

The city has received several inquires regarding caterpillars, webworms, canker worms and inch worms, attacking or killing trees. Insect infestations are cyclical and don’t generally recur year after year, Fox said.

He cautions residents from grabbing the chainsaw to start chopping down trees or go on bug hunts. Most of the trees under attack will survive, Fox said.

“It’s a nuisance, but it’s nature (some years we have a bountiful crop of bluebonnets, other years it’s caterpillars),” he added.

What is going on with hackberry trees?

Hackberry is likely the most obvious and hardest hit tree.

The hackberry leaf roller caterpillar is the main cause of damage to hackberry trees and their leaves, Fox said. The small and thin caterpillars will be enclosed in a thin network of sticky webbing.

This instance of hackberry invasion is similar to what occurred in 2015 across North Texas, he said. Then, caterpillars were attacking hackberry trees across Denton, Tarrant and Dallas counties.

Like in 2015, this past summer had a long and hot dry spell followed by intense rains and warm weather. The 2015 outbreak occurred around late August, so the time frame’s are comparable, Fox said.

Nevertheless, unless a hackberry tree is in poor condition due to drought, mechanical injury or pests, it does not warrant removal and should be just fine, he said. Although the tree will likely not re-leaf this year since it is almost October.

“The city is not treating for these insects so the caterpillars will continue what they are doing and the trees should be normal and healthy next year,” Fox said.

These particular caterpillars are host specific, meaning that hackberries are the target and most every other tree will be left alone, Fox said.

What else is attacking trees?

Along with hackberries, the city is experiencing several other less noticeable infestations of caterpillars.

Fall webworm, fall cankerworm, leaf-roller worms and others, may all be present now and attacking pecan, oak or elm trees, Fox said.

The city is again not treating for these caterpillars and trees should return to normal next year, Fox noted.

What can homeowners do about the caterpillars?

While the caterpillar situation is more of a nuisance than a problem, there are a few things homeowners can do about the insects.

Products containing pyrethroids or spinosad are generally effective against caterpillars and other insects, Fox said. Caterpillars in particular might take a little more work to spray with the pesticides since they are generally veiled in a protective sticky webbing.

“None of these insects or larvae should pose a risk to human health, but they are messy,” he added.