Fall Web-Worms and Prevention

Fall brings cooler weather pretty leaves and  those horrible webs that seem to cover the trees and deter from the pretty leaves.

 

Commonly referred to as bagworms or webworms.  Hyphantria cunea are the type of webworms that make their appearance during late summer and autumn.

 

The Good News                      autumn-oak-foliage

The good news is these little guys don’t generally  hurt the trees, and are just more of an aesthetic problem. Webworms only munch on the leaves of the tree, which is already about to go dormant for the winter and shed it’s leaves anyway.

 

The Bad News               20160921_151813

The bad news is that webworms range from south Canada across the U.S. and love just about every kind of hardwood tree. Hickory, oak, pecan, even redbud and some fruit trees. The list goes on encompassing almost all deciduous trees.

 

Appearance

More than likely before the worm or adult moth is spotted we will notice the nest. Nests are composed of spider like string thread that is woven together with twigs, leaf debris and excrement from the worms. They gradually become larger and encompass more leaves, the larger nests can reach up to 3 feet.

 

The adult moth is most commonly white with darker spots on the wings.

 

Caterpillars can grow up to 1 inch long and colors vary by climate and location. Most caterpillars  have a yellow to green colored body with a mottled strip or two running running along the length of them. Their heads can range in color from black to a reddish hue.  

 

Life Cycle                       sack-worms

 

The eggs are laid on the underside of leaves. Clutches contain a couple hundred eggs that hatch out in about a week. Young caterpillars build their own webs while they feed on leaves. This stage will last about a month and a half. As winter comes closer the grown caterpillar weaves a dark brown  cocoon about ⅜ of an inch long either in leaf debris or under some loose bark. It will survive the winter in its pupa form.  

 

Webworm Control

 

More often than not little is done to control these pests. Expert opinion is that they cause little damage to trees, that are preparing to shed their leaves and go dormant for the winter. So why not let them be.

 

Tree safety aside making your home in a tall tree and out of reach keeps most humans from braving the awkward scenario of removing them. But what if some of us do want to remove them from interrupting our fall leaf experience.      wren-feeding-young

 

  • Natural Enemies. Webworms have a lot of them. Including birds, if you can reach a web  cut it open to give birds easy access.
  • Make Your Yard More Bird Friendly.  Adding bird feeders, houses and baths will help you attract mother nature’s first line of defense.
  • Keep Trees Pruned. Pruning dead branches will help deter them especially if you use pest spray afterwards 
  • Keep Debris Picked UP. Leaf and other fall debris provide hiding places for insects, and prevent natural predators from getting an opening.

     

  • Sevin Dust or other farm powder can be used as soon as you notice a problem and repeat 10-14 days later. The construction on the web makes nests water resistant and prevents most sprays from penetrating.

     

  • Let Them Be.