What is eating my tree's leaves?
Leaves reduced to holes, notches, or lace; small cone-shaped bags hanging from evergreen twigs; or silk webbing wrapped around branch tips.
Not an emergency this afternoon, but the window for a useful response is measured in weeks. Left alone, most of these get more expensive rather than less.
Chewing on a deciduous tree is almost always cosmetic — an oak or elm can lose a third of its foliage and finish the season without complaint. Bagworms on an evergreen are the exception, and a serious one. Junipers, cedars, spruces, and pines cannot regrow needles from bare wood, so a heavy bagworm year kills the tree outright.
What this looks like
Read the damage and the structure together. Bagworms build a spindle-shaped bag out of the tree's own foliage and drag it around as they feed, so a heavily infested juniper looks like it is hung with small brown cones. Fall webworm wraps the outer ends of branches in loose gray silk and feeds inside. Eastern tent caterpillar builds a tight silk tent in a branch fork in spring. Japanese beetles skeletonize leaves, leaving the vein network behind like lace.
- Two-inch bags covered in bits of the host's own needles or leaves, hanging like ornaments
- Loose silk enclosing the last foot or two of a branch, full of frass and shed skins
- A dense silk tent packed into a branch crotch, with caterpillars fanning out to feed in the morning
- Leaves eaten down to the veins, with metallic green-and-copper beetles clustered on what is left
What causes it in Kansas
Roughly in order of how often each turns out to be the answer here. The line under each one is what separates it from the others — open a cause for the detail.
1Bagworms
How to tell: Cone-shaped bags built from the host's own foliage. Pull one open and it is silk-lined with a caterpillar inside, not an empty seed cone.The most damaging tree insect in Kansas landscapes after the emerald ash borer, and the most preventable. They favor eastern red cedar, junipers, spruce, and pine but also feed on honeylocust, maple, and sycamore. Timing is everything: control works while larvae are small and feeding, and nothing sprayed in August will reach an insect that has already sealed its bag.
2Fall webworm
How to tell: Webbing at the tips of branches, appearing after mid-July, enclosing the leaves it is feeding on.The late-summer webs on walnut, mulberry, hackberry, and pecan that prompt more phone calls than any other Kansas insect. The damage is trivial: by August a tree has already banked most of its food for the year.
3Eastern tent caterpillar
How to tell: A tight, permanent silk tent in a crotch rather than at a branch tip, and it appears while other trees are still leafing out.A spring insect of cherry, crabapple, and plum. Tents appear at branch forks in April, the caterpillars leave to feed and return, and by June the whole event is over.
4Japanese beetle
How to tell: Lace-like leaves with the veins intact, and the beetles themselves — half an inch, metallic green with bronze wing covers — sitting on the damage.Established in eastern Kansas and pushing west. Adults feed in groups on linden, elm, birch, roses, and grapes through late June and July, skeletonizing leaves from the top of the plant down.
5Sawflies and leaf beetles
How to tell: Feeding is concentrated on one species of tree in the yard while everything else is untouched.Elm leaf beetle, walnut caterpillar, and pine sawflies each produce their own signature damage. Most run one or two generations and are handled by weather and natural enemies.
6Deer, rabbits, and squirrels
How to tell: Damage stops at a level line — roughly four feet for deer, eighteen inches for rabbits — and there is no insect anywhere on the plant.Browsing takes whole leaves and shoot tips off young trees at a consistent height, and rabbits clip stems at a clean angle in winter.
What to do, and what to avoid
Safe to check yourself
All from the ground — no ladder, no saw.
- In June, look closely at any juniper, cedar, or spruce for bags the size of a grain of rice — that is the moment control still works
- Open a web or a bag rather than guessing from the ground
- Estimate what fraction of the canopy is actually gone; under a third on a deciduous tree costs the tree very little
- Check whether the tree is an evergreen, because that single fact changes the urgency completely
What not to do
The responses that make this one worse or permanent.
- Do not burn webs out of a tree — it is a genuine fire and injury risk, it wounds the branch far worse than the caterpillars do, and open burning is restricted in many Kansas jurisdictions
- Do not spray for bagworms in August; by then the bags are sealed and the material lands on nothing
- Do not treat fall webworm on a large tree in September, when the season is over anyway
- Do not use a broad insecticide on a flowering tree while it is in bloom
When to contact an arborist
Whatever this narrows it down to, the assessment that decides what happens next has to happen at the tree. Why that is
Common questions
Can I just pick the bagworms off?
Can I just pick the bagworms off?
Yes, and it is the best control there is on a small tree. Handpick from fall through mid-May and drop them in soapy water — each bag you remove in winter is up to a thousand eggs that never hatch. Cut them off rather than pulling, since the silk band can girdle a twig.
Will my evergreen grow back after bagworms strip it?
Will my evergreen grow back after bagworms strip it?
Largely no. Junipers, cedars, spruces, and pines have very limited ability to produce new growth from bare wood, so a defoliated branch usually stays bare. This is the whole reason bagworms are treated as a serious problem here and fall webworm is not.
Is Bt worth using?
Is Bt worth using?
Bacillus thuringiensis works well on young caterpillars, is specific to them, and is the reasonable first choice on bagworms in early June. It becomes progressively less effective as larvae grow, which is another way of saying that on bagworms the calendar matters more than the product.
Kansas Tree Guide is an independent educational resource. Nothing on this site replaces an on-site assessment by a qualified arborist or tree-care professional. Last reviewed August 2026.
Often seen alongside this
A second symptom narrows the cause faster than more detail about the first.
Not what you are seeing? Work the symptom guide again.