Bumper crop of inchworms coats the Triangle

jshaffer@newsobserver.comMarch 28, 2012 

  • Entomologists suggest banding trees in November and December to block the cankerworm moths from crawling from the soil to the tree tops to lay eggs. Sticky material should be applied to the band to stop their progress. Such agents – Tanglefoot is one – can be bought in garden stores.

— They parachute down from tree branches, landing in hair, on shoulders and in shirt pockets – a deluge of hungry inchworms awakened by spring.

So many of the green wrigglers – cankerworms, by their official name – have landed in the Triangle this spring that their strands of silk are blocking sidewalks.

At the Wake County cooperative extension office, nearly every visitor arrives with an insect visitor dropped from a tree out front. In Durham, Matthew Palmer believes he can actually hear them munching leaves in his Trinity Park backyard.

“I’m reminded more of the locusts from ‘The Good Earth’ than the zombies from the ‘Walking Dead,’ ” he wrote in a neighborhood Listserv. “Although, these inchworms seem to have zombie-like qualities.”

No exact count is available, but it’s clear from walking the streets that warm weather has drawn out worms in rare quantity, said Steve Frank, entomology professor at N.C. State University.

Two varieties are hatching in abundance: the fall cankerworms, whose eggs survived the mild winter on the ground; and the spring cankerworms, which hatch just as leaves are sprouting – especially willow oak. Part of the larger inchworm family, you can expect them for about five weeks total. Once they’re finished being caterpillars, if they don’t wind up as a songbird’s breakfast, the worms turn into wingless moths.

“We’ve seen tons of them,” Frank said. “There’s sidewalks on campus where their silks stretch all the way across the sidewalk.”

Worm onslaughts are familiar in Charlotte, where the bugs multiplied so quickly in 2008 that the city sprayed chemicals from the air to save the trees, using five planes to cover 63,000 acres at a cost of $1.1 million. Reports from the Queen City in that year showed more than 1,000 worms collected from single trees.

But Frank said serious defoliation is unlikely in the Triangle. Big willow oaks can withstand this level of nibbling.

Worm gore is another hazard. Casually swiping insects off shoulders can be messy.

“At least two or three times a day, I’ve got one on my shoulder,” said James Henderson, who works at Logan’s garden center in Raleigh. “I was going to take one outside, and Robert Logan slapped on the shoulder and asked, ‘How you doing?’ My hand came back with a green streak.”

Then there are the droppings, also known as “frass.”

In Durham, Cat Warren explains her unpleasant encounter on the Trinity Park Listserv:

About those black specs…

“A couple of people have suggested that they can hear the sound of the inch worms feeding in their yards,” she wrote. “I, too, thought that was the case, until I realized something even more disgusting. That sound is caterpillar poop falling. If you go to where they are feeding with some alacrity, you will see little black dry black specs all over the ground. ... You can actually feel it fall on you.”

If nothing else, they’re fun to watch as they bunch themselves together and expand – making slow but stable progress, inching through life. Staff researcher Peggy Neal contributed to this report.

Shaffer: 919-829-4818

News & Observer is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service