BATON ROUGE, La. (BRPROUD) – In Louisiana, residents may spot spider webs on some of their plants this time of year. These “webs are spun by caterpillars of the fall web moth,” according to the LSU AgCenter.

“If a homeowner depends on the tree to be aesthetically pleasing, provide shade, or produce fruit or nuts, they should control the fall web moth because it will defoliate the leaves, thus impacting all three,” said Dr. Aaron Ashbrook, assistant professor of urban and Pieri-Urban Entomology at LSU.

The AgCenter said the netting protects the caterpillars from predators such as spiders, birds, lizards, larvae, parasitic wasps and small mammals.

“After fall web moths hatch from their eggs, they immediately spin a small web in the area where they feed to protect themselves,” Ashbrook said.

“Initially, the webs are only tied in the feeding areas and as they move along the branches, they spread the web over new leaves,” he explained.

Getting rid of this sticky structure is not so easy. The LSU AgCenter said, “The web also makes chemical control with insecticides more difficult.”

Ashbrook said: “When you spray a water-based insecticide, the droplets get stuck in the fabric and don’t penetrate properly.”

If you’re having trouble getting through the nets, Ashbrook recommends adding liquid dishwashing detergent to the insecticide and trying a high-pressure sprayer.

If you want to try insecticides, know that there are “several classes of insecticides registered against fall web moths,” according to Ashbrook.

He said: “Insecticides containing indoxacarb, spinosad and tebufenozide will help protect some of the predators that feed on the fall spider moth while keeping the pests under control.”

Ashbrook offered another option for dealing with the fall dust moths.

“Bacillus thuringiensis is effective against fall moths,” he said. All you have to do is spray it on the leaves and it will kill the insects that try to eat them, Ashbrook said.

You don’t want to spray chemicals?

According to Ashbrook, you could also remove the nets yourself “and place the nets and insects in a bucket of soapy water for several hours.”

The LSU AgCenter said residents can use a leaf trimmer or garden shears if the webs are deep enough to reach. They suggested trimming only the webbed branches.

Residents may also choose to leave the fall web moth alone. According to the LSU AgCenter, their webs are “rarely harmful to the tree.”

Ashbrook said: “When the bagworms are in a dense woodland area, their impact is less noticeable and less severe, so control may not be necessary in areas with many trees.”

He said the first wave of moths will be seen around mid-March or April each year.

Then they lay the first eggs, Ashbrook said. He said from that point on, “they’ll have four or five generations until fall.”

In the northern states, the moths are found in late summer and fall. Ashbrook said, “The fall moths migrate to the northern United States and show up around fall time, hence their name.”

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