AgriLawn's Seasonal Weed Control and Fertilization Blog
Fall Web Worms Already?
You may have noticed the fall webworms already at it this summer. These nuisance pests affect various trees in our great state, most commonly persimmon, pecan and walnut. With fall webworms out this early we could see infestation of oak, birch, sweet gum, sycamore and red bud trees as well this season.
Even though webworms are feeding on the foliage of these trees they are not a major threat to the health of established trees. They are really more of a nuisance pest causing unsightly webs within the tree canopy. Two forms of fall webworm are found in Oklahoma. The larval stage (caterpillars) will feed on tree foliage within spun webs now throughout early fall. They will overwinter in the soil and emerge to pupate in late spring before laying eggs again early next summer.
The best control practice for fall webworms is simply removing the webbing itself when it’s within reach. Always observe proper cutting methods when removing tree branches to avoid unnecessary tree stress. There are several predatory insects helping keep webworm populations down so chemical control can/should be a last resort. If mechanical removal of the web cannot be obtained chemical control may be considered. When spraying for webworms it is important applicators really blast the webbing. The webs are tough and sufficient product must penetrate into the interior to be effective. Keep in mind, even though successful elimination of larvae will occur after treatment, the unsightly webbing will still remain.