It has begun. The annual appearance of webbing in trees along the roadways and woods in the county has started.
Those are webworms, a native insect that spans as far north as Canada to as far south as Mexico. And as the days get shorter and shorter, they will become more prominent in trees around the county.
Fall webworms are caterpillars that use the silk webbing to protect them from predators as they feed on leaves of more than 100 different types of trees. Some of the most common trees webworms infest are black walnut, mulberry, elm, sweetgum, willow, apple, ash and oak.
The sign of fall webworms in a tree are relatively easy to spot. They will create a nest at the end of branches and expand the size of the nest to meet their nutrition needs.
In general, fall webworms are nothing to be too concerned about. If a tree is healthy, it will withstand an infestation. Most deciduous trees can tolerate losing most of its leaves, especially during this time of year when fall leaf drop is just around the corner. A time to be concerned with an infestation is when small trees are becoming established or when trees are sick or stressed.
In general, the damage webworms cause in hardwoods is purely cosmetic and does not cause long-term problems to the health of the tree.
With that in mind, chemical control is generally not required. But if you need to treat an infestation, start with insecticidal soaps, horticultural oils or bacillus thuringiensis. These products will provide control of the caterpillar when it is small, but not harm other insects or predators who feed on them. If you have large caterpillars on a tree, consider using bifenthrin or cyfluthrin.
When using any of these products, you must make contact with the worms inside the webbing. So be prepared to break into the nest to expose the mass of caterpillars inside by using a broom handle or something of that nature.
Michael Wheeler is county extension coordinator for the UGA Cooperative Extension office in Hall County. You can contact him at 770-535-8293, www.hallcounty.org/extension. His column appears weekly and on gainesvilletimes.com/life.