Fall webworm in shade and fruit trees
Most webs need no treatment at all. Where one does, on a small ornamental or a pecan, Btk only works if the caterpillars eat it and they feed inside the web. Spray as soon as colonies appear, while webs are small. Larger webs are harder for the spray to get into, so Clemson advises covering the foliage around the web. A web you can reach is quicker to prune out by hand. The Monterey label says Btk does not harm honeybees, ladybugs or birds when used as directed; keep spray and runoff out of water.
At a glance
- Damage
- Loose silk webs over branch tips; leaves skeletonised inside
- Type
- Chewing
- Settings
- Garden, Field
- Threshold
- See profile
- Ally
- Bacillus thuringiensis kurstaki
- Rate
- Label rate — 4 tsp per gallon of water on the Thuricide and Monterey B.t. shade-tree and ornamental directions
How to confirm it
Loose, dirty-grey webs enclosing the ends of branches in summer and autumn, with hairy pale yellow to greenish caterpillars feeding inside. Eastern tent caterpillar builds a dense tent in a branch fork in spring, and feeds outside it.
Identification, lifecycle, degree days and every control option are on the full Fall webworm profile. Not sure it is this pest? Answer four questions about the damage.