Tree problems · Insect
Fall Webworm: signs and what to do
Fall Webworm is an insect pest, often seen on walnut and pecan, hickory, black cherry. Look for: loose, silky webs that enclose leaves at the ends of branches.
General information, not a diagnosis. A certified arborist or your county extension office can confirm.
- Insect
- Walnut and pecan
- Hickory
- Black cherry
- Sweetgum
- Mulberry
- Sycamore
Signs to look for
Tick what you see. More ticks make it more likely, but only an on-site look can confirm.
0 of 6 signs ticked. Ticks stay in this browser only.
Season
The webs show up from mid to late summer and into fall, depending on the region. The caterpillars then drop to the ground and spend winter as pupae in leaf litter or soil.
How it spreads
Moths lay egg masses on leaf undersides in summer. Caterpillars hatch, spin a web and keep enlarging it as they feed. Moths fly, so nearby trees can be hit too.
Where it is found
Fall webworm is a native insect that extension services report across much of the US on many kinds of trees. Check your state official map; ranges change.
Official sources
What to do
- 1
Know that the damage is mostly cosmetic. Late-season feeding happens when trees are getting ready to drop leaves anyway.
- 2
Reach small webs with a pole pruner or a stick and tear them open so birds and wasps can reach the caterpillars. Wear gloves and eye protection.
- 3
Prune out small webs on low branches and bag them. Do not burn webs in or near a tree.
- 4
Never use fire or a torch on a web. It hurts the tree and is a safety risk.
- 5
If a spray is needed, use a product labeled for caterpillars on that tree and follow the label. Ask a licensed pro when in doubt.
Safety first: do not climb, do not cut near power lines and do not use a chainsaw on storm-loaded wood. Call the utility for downed lines and 911 if anyone is in danger.
Prevention
Keep trees healthy with proper watering and mulch. Check trees in mid to late summer and tear open small webs early. Encouraging birds and beneficial insects helps keep numbers down.
When to call a pro
Call a pro if webs are high in a large tree you cannot reach safely, if the tree is young or already weak, or if you are not sure the web is fall webworm and not a more serious pest. Do not climb or use a ladder near power lines.
Not sure who to call? Read how to hire a tree service or check is my tree dangerous?
Trees it affects
Usually seen on: Walnut and pecan, Hickory, Black cherry, Sweetgum, Mulberry, Sycamore, Birch, Maples, Many other hardwoods.
- Black walnut
- Pecan
- Shagbark hickory
- Black Cherry
- Sweetgum
- Red Mulberry
- American sycamore
- River Birch
- Red Maple
- Boxelder
See all species in our tree library, or pick a tougher tree with the tree picker.
For tree companies
How to explain fall webworm to a customer
Fall webworm webs scare homeowners, and the honest message is that the tree usually recovers. Explain the timing, offer to remove small webs or treat a young tree, and say clearly when no treatment is needed. A calm, honest visit builds trust and often leads to other work.
Send this page to the customer after your visit so they can read the signs in plain words. See also selling plant health care and the job photo checklist.
Questions
What are the big webs on the ends of my tree branches?
They are most likely fall webworm nests. The caterpillars feed inside a loose web that grows through late summer and fall.
How do I tell fall webworm from tent caterpillar?
Fall webworm webs are at branch tips and show up late in the season. Eastern tent caterpillar tents are in branch forks and show up in spring.
Will fall webworm kill my tree?
A healthy tree usually does not die from it. The feeding comes late in the season, so the harm is mostly how the tree looks.
Should I burn the webs?
No. Fire can hurt the tree and start a larger fire. Tear the web open or prune it out and bag it.
Do I need to spray?
Usually not for a mature tree. Spraying is mainly for young or weak trees, and it needs the right product used by the label.
Are the caterpillars dangerous to touch?
They are hairy and some people get skin irritation from touching them. Wear gloves and avoid touching them with bare skin.
Can Lirevon diagnose fall webworm on my tree?
No. Lirevon is a remote marketing team for tree service companies and does not do tree work. This page is general information, not a diagnosis. A certified arborist or your county extension office can confirm what is wrong with your tree.
How do I find a good local pro for this?
Search Google Maps for certified arborists or tree services near you, read their reviews and ask for proof of insurance. Get two or three written quotes. Our guide on how to hire a tree service lists the questions to ask.
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