Tree problems · Insect
Periodical cicada damage: signs and what to do
Periodical cicada damage is an insect pest, often seen on oaks, maples, dogwood. Look for: browned, dead leaves at the tips of branches (called flagging).
General information, not a diagnosis. A certified arborist or your county extension office can confirm.
- Insect
- Oaks
- Maples
- Dogwood
- Young landscape and nursery trees
- Many other hardwoods
Signs to look for
Tick what you see. More ticks make it more likely, but only an on-site look can confirm.
0 of 5 signs ticked. Ticks stay in this browser only.
Season
Periodical cicadas come out every 13 or 17 years, usually in late May or early June, when the soil warms to about 64 degrees F at 8 inches deep. Flagging shows up a few weeks after egg-laying.
How it spreads
Adults do not travel far. Females cut slits in twigs and lay eggs there. When the eggs hatch, the young drop to the ground and burrow into the soil.
Where it is found
Periodical cicadas come out in broods in certain parts of the eastern and central United States in certain years. Check your state official map and your county extension office; ranges change.
Official sources
What to do
- 1
Know whether your area is expecting an emergence. Ask your county extension office.
- 2
Do not plant new small trees or shrubs just before or during an emergence, as one extension source advises.
- 3
Cover small valuable trees with fine mesh netting, openings no bigger than about 1/4 inch, before the cicadas come out. Tie it at the trunk so they cannot climb up from below.
- 4
Leave the netting up until adult activity ends.
- 5
Let flagged branches on mature trees fall on their own or rake them up. Healthy mature trees usually recover.
- 6
Do not use insecticides to protect trees without advice from your extension office.
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
Plan planting dates around known emergence years. Net young and valuable trees in time. Keep trees watered and healthy so they can recover from twig loss.
When to call a pro
Call a certified arborist if a young tree has lost most of its branch tips, if large dead branches hang in the crown, or if you want help netting tall trees safely. Hanging limbs over a house or path should be handled by a trained, insured crew.
Not sure who to call? Read how to hire a tree service or check is my tree dangerous?
Trees it affects
Usually seen on: Oaks, Maples, Dogwood, Young landscape and nursery trees, Many other hardwoods.
- White Oak
- Northern Red Oak
- Pin Oak
- Red Maple
- Sugar Maple
- Flowering Dogwood
- American Linden
- Bradford Pear
See all species in our tree library, or pick a tougher tree with the tree picker.
For tree companies
How to explain periodical cicada damage to a customer
Tell owners plainly that egg-laying damage is mostly a risk to young trees and that mature trees normally recover. Do not sell fear or sprays. Offer netting advice in the weeks before an emergence and help with clean-up of hanging flagged branches afterward.
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
Do periodical cicadas hurt trees?
Adult feeding is minor. The main harm is from egg-laying, which cuts twigs and causes flagging. Young trees are most at risk.
Will my mature trees be okay?
Extension sources say healthy mature trees usually recover and flagging does not kill them.
What is flagging?
It is when the tips of branches turn brown and die after the females lay eggs in the twigs. The leaves stay on for a while and look like flags.
How do I protect a young tree?
Cover it with fine mesh netting before the cicadas emerge, tie it at the trunk, and leave it up until they are gone.
Should I spray?
Ask your extension office first. Many sources focus on netting and good timing of planting rather than sprays.
When should I plant new trees?
Extension sources suggest avoiding planting just before or during an emergence year. Ask your county extension office for the timing in your area.
Can Lirevon diagnose periodical cicada damage 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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- Drought Stress (Other damage)
- Frost cracks (Other damage)
- Herbicide damage (Other damage)