WICHITA, Kan. (AP) - Silky webs so large they look like Halloween decorations have overtaken entire branches, or even entire sections, of Wichita trees in recent weeks.
The Wichita Eagle (https://j.mp/2cUjFi9 ) reports that the webs come from caterpillars appropriately named fall webworms. The caterpillars turn into moths, but produce massive webs during the larva stage.
Sedgwick County has seen higher-than-normal numbers of fall insects that are covering trees with webs, eating grass from lawns and biting people.
One week, most callers to the Sedgwick County Extension Office wanted to talk about the invasion of the webworms.
“That’s the hot topic out there,” said Matthew McKernan, an extension horticulture agent.
Here’s what you should know about fall webworms, fall army worms and oak itch mites.
What they are: Fall webworms are a type of moth known particularly for its larval stage, when it creates silky webs that cover entire branches of trees.
What they do: The caterpillars stay inside the webs to ward off predators and birds.
The webworms have two generations of caterpillars each year - the first generation between late June and early July and the second generation right now.
McKernan said most people don’t notice the first generation because the second has more caterpillars, with larger webs and more feeding.
Each female webworm lays between 400 and 500 eggs at a time, McKernan said, adding, “You can see how that quickly becomes a problem.”
McKernan said webworms are particularly prevalent this year - possibly because of Kansas’ wet summer and mild winter.
He said the caterpillars’ large, silky webs can encompass entire branches of trees.
“It’s a very common sight, especially across Wichita,” he said.
On the upside, webworms don’t pose threats to people or pets.
Where they are: Webworms feed on shade trees, ornamental trees and fruit trees, but not on conifers or evergreens.
The caterpillars eat leaves from the tree and can completely defoliate the tree, but generally won’t kill the tree.
McKernan said webworms can be seen all over Wichita, but are more common in southern areas of the state.
You can get rid of them by removing any branches covered by webs and seal the branches in a plastic bag before disposing of them in the trash. That prevents the caterpillars from crawling into another tree.
For branches that are hard to reach, use a long stick or pole with a perpendicular nail at the end. Place the nail into the web, twist the pole a few times, and then pull the web out of the tree. The caterpillars usually come out with the web.
Some chemicals are available to control webworms, but those chemicals require high-pressure sprayers and must be applied when the webs are still small, before much of the leaves have been eaten.
The webs are largely harmless, but unsightly.
If you leave it in the tree, you just look like you’re ready for Halloween.
Matthew McKernan, an extension horticulture agent
“If you leave it in the tree, you just look like you’re ready for Halloween,” McKernan said.
What they are: Fall army worms are caterpillars that eat grass.
Younger fall army worms are about a half inch to three-quarters of an inch long. The older caterpillars are about an inch and a half long.
The caterpillar’s body varies in color from green to dark black with visible light stripes along the length of the body. The dark-colored head has a light-colored, upside-down “y.”
What they do: Typically, fall army worms are found in areas surrounded by agricultural fields, but this year, McKernan said, Wichita has seen higher populations of the caterpillars in lawns in Wichita, especially west and north Wichita.
“(The caterpillars) can do quite a bit of damage in a short period of time,” he said.
Typically, the caterpillars will chew the sides of a blade of grass.
But large populations of fall army worms will eat blades to the ground and kill the grass.
“In those situations, you can notice brown areas in the lawn even in a 24-hour period of time, or less, if you have a large population,” McKernan said.
Matthew McKernan, an extension horticulture agent
Nonetheless, he said, the fall army worms prefer to feed on the blade, rather than kill the grass entirely.
Where they are: McKernan said most people won’t see the caterpillars because they will live in the soil and feed at night and during overcast days.
McKernan said fall army worms usually appear in Kansas for only about three weeks during the year, which he presumes began about a week ago, as part of the insect’s migration south.
How to get rid of them: People can spray lawns with either spinosad, permethrin, dylos, carbaryl, or cyhalothrin, to rid the caterpillars from the area.
What they are: Oak leaf itch mites are tiny insects that feed and live on the outer edges of the leaves of oak trees during summer months and live in soil during winter months.
What they do: During late summer and fall, the mites fall from trees down to the soil. These insects have no control over where they land and sometimes end up on people or pets.
In the spring, the mites change form into the adult stage and fly back up from the soil to tree leaves.
McKernan said the mites are so small, they’re usually invisible to the naked eye.
Oak leaf itch mites are about 1/125 of an inch and usually invisible to the naked eye.
The bugs are about 1/125 of an inch.
McKernan said most people won’t feel the bite until about 10 to 16 hours later. Then a raised red area will form on the skin with a small, centralized blister that itches and is painful when scratched.
But the good news is they’re typically just nuisance itches, unlike chigger bites which can destroy tissue.
Oak leaf itch mites, McKernan said, bite areas of exposed skin or loose clothing, whereas chiggers bite areas underneath tight clothing, like waist bands.
Where they are: Oak leaf itch mites can be found statewide in pin oak trees and trees in the red oak family.
How to get rid of them: McKernan said sprays with DEET can sometimes help ward off oak leaf itch mites, but the best protection likely comes from covering up.
“A mosquito is going to actively chase you down,” McKernan said. “The oak itch mite has no control over where it lands and where it goes, so how you protect yourself is a little different.”
He recommends wearing long sleeves and gloves while working outside near oak trees. Taking a shower and changing clothes after being around oak trees also will help, McKernan said.
The bites can be treated much like mosquito bites with cortisone cream, calamine lotion or Benadryl, if needed. He said the bites generally go away in five to 10 days.
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Information from: The Wichita (Kan.) Eagle, https://www.kansas.com
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