Now that they're done feasting, webworms are falling from trees on their way to becoming moths.
By BETH N. GRAY
Published October 11, 2003
[Times photos: Lance Rothstein]
Berl and Pamela Merrill's sweet gum tree, above and below, became host this year to innumerable webworms, which have eaten their way through its foliage.
BAYPORT - Brenda Kramer was angling for bait fish in the canal behind her house when she felt something on her arm. It turned out to be lots of somethings: fuzzy, inch-long worms were falling from the trees overhead.
"I've been brushing at my arms for two days," Kramer said with a shudder. "They're disgusting."
The creepy critters, commonly known as fall webworms, dropped out of the treetops in such abundance this week that they covered the side of her Palm Grove Colony house, Kramer said.
A few doors away, Berl Merrill had the same skin-crawling experience.
"They're all over. That van next door was covered with them," he said. "They're in all the trees and bushes."
A sweet gum at the edge of the Merrills' driveway is usually the last tree to shed its leaves in the fall, said his wife, Pamela. Already it is completely defoliated and wrapped in a cocoon of grayish Halloween-like webbing. Nearby, a Norfolk pine, a banana tree and a large ligustrum are similarly enveloped in web.
"We've never seen an infestation like this," said Pamela Merrill, a 26-year-resident of Palm Grove Colony.
University of Florida extension entomologist John Foltz said webworm-friendly weather played a part in their increased ranks this year.
"These are critters that are more abundant some years than others," Foltz said. "They found conditions just right. ... Spring and summer generations had a high survival rate."
To combat the worm infestation, the Merrills bought a chemical spray but decided not to use it after they realized the spray could harm pets and humans.
"We've got kitties," Berl Merrill said.
Instead, he got out his vacuum and sucked as many of the worms and as much of their web as he could reach on the big sweet gum.
"As crazy as that sounds, vacuuming is one of the best ideas," said Jim Moll, Hernando County Extension urban horticulturist, who recommended another environmentally safe ploy: drown webworms in soapy water.
Birds and lizards don't eat the worms, which are the larval stage of a type of moth, according to Foltz.
Palm Grove Colony resident Kramer knows that from experience. She watched a worm inching along a fence rail toward a gecko, and it was the lizard that backed off, she said.
"They're not the most tasty creatures," Moll said of the larvae. "They can taste bitter."
Also, the bristly hairs covering their bodies have no snack appeal to regular predators of other larvae.
"I think we're going to lose and the worms will win," Pamela Merrill said.
But Moll had good news for her. When the worms begin falling out of the trees, their feeding is pretty much over and their damage is done, he said. They will then mate and spend the winter in the pupal stage before they metamorphose into small white moths, sometimes bearing black spots, in the spring.
The moths have no way to chew leaves, so instead they feed on nectar, causing less destruction. But they do reproduce.
"There's no way to prevent it for next year," Moll said. "We have tens of thousands of acres (the moths) could fly out of."
Pamela Merrill worries the hardest-hit trees and shrubs won't live.
Several factors will determine that, Moll said. Established, healthy trees should survive to leaf again. For trees nearing their winter shutdown, defoliation this late in the season is not so stressful. The intrusive munching will be harder on shrubs and young trees, he said.
University of Florida extension entomologist Eileen Buss urged homeowners who want to nip next year's hatch in the bud to spray with a biological agent, Bacillus thuringiensis, variety kurstaki.
The product lists the active ingredient on the label as B.t.k. It is specific to several larvae but is friendly to people, pets and the environment. It's most effective on small caterpillars and must be sprayed directly on the worms or foliage, Buss said.
Moll urges vigilance on the part of tree owners who want to prevent trees from being overrun by larvae.
"Look at your trees in August," said Moll, who knowledged that there limits to what homeowners can do.
Meanwhile, entomologist Foltz took a lighter view of the defoliation.
"I personally like to think this is more leaves I don't have to rake," he said.
