What are they and how to get rid of them

Spring and summer can bring many problems to Houstonians, such as excessive heat, humidity, flooding and webworms.

Web worms are usually spotted in large clusters on the sides of trees, houses and cars. Although harmless, they can be difficult to get rid of and their congregation can be an eyesore, but insect experts offer potential solutions.

Webworms, also known as tent caterpillars, are small, fluffy insects commonly found in trees in the Houston area. Bedbugs often reside on the bark of trees and lay up to 15 eggs under the leaves.

The caterpillars group together and form webs from their feces, creating the tent-like structure from which they get their name. Webworms have adapted to Texas’ extreme weather, making it unlikely that extreme heat will harm them, said Molly Keck, an entomologist at Texas A&M AgriLife.

“Rain can help reduce their populations by knocking them off trees if it’s raining hard or it’s windy or things like that,” she said. “They have been around for a long time and have found a way to acclimate to Texas weather, so a significant weather event is unlikely to kill them.”

The insects are attracted to more than 100 different types of trees, including pecan and mulberry trees commonly found in the Houston area. However, the caterpillars are not native to Houston and can be found throughout the state, Keck said.

Because of their light weight, moths often blow in the wind onto tree branches and the sides of houses and cars, which can be an annoying eyesore.

Webworms have multiple generations throughout the year and are most abundant in the fall. They mate in spring and usually begin to appear in mid to late summer. The species is best able to survive in areas with mild winters, which allow all stages to continue to develop.

Webworms feed on the leaves of trees, however, if a tree is strong and healthy it should survive. Diseased trees and young trees are at risk of death from the insect’s feeding habits. Webworms, which thrive in dry turf, can pose a risk to Houston gardens and turf. Watering often and cutting the grass high can help solve the problem, as can sprinkling a solution of liquid dish detergent in water on the grass.

Web worms are non-toxic and pose no danger to humans other than being eyesores. However, if killed, caterpillars leave a sticky residue on surfaces that can be difficult to clean. Houstonians are recommended to immediately wash their hands with soap and water if they come into direct contact with the insects.

Although web worms are harmless on their own, they have been known to cause power outages in the past. By covering parts of electrical equipment, insects can disrupt insulation or blow fuses, according to Sam Houston Electric Cooperative.

Unlike some other caterpillars, moths turn into white moths rather than butterflies. It takes about six weeks for web worms to complete their life cycle.

Pesky insects can be eliminated with glue traps and garden hoses, however, pest control may be necessary for larger clusters of moths.

Keck recommends residents let nature take its course, but they are able to speed up the process by breaking up the clusters formed by the moths, because “this will allow birds, lizards and other natural enemies to penetrate and help bring down the population naturally. »

Some granular and chemical solutions, such as Bug Out, Cyonara 9.7 or Spectracide Triazicide, can also eliminate insects. The key ingredient in these solutions is the insecticide bifenthrin. However, high demand for these solutions may lead to a shortage in local businesses.

“No matter what you use, it’s best to break up these webs somehow because the webbing is pretty waterproof so it’s very difficult for you to use pesticides to penetrate,” said Keck. “Opening these webs is vital, whether you do it naturally, letting nature take its course, or use pesticides.”