Tree problems · Insect
Aphids: signs and what to do
Aphids is an insect pest, often seen on maples, oaks, crape myrtle. Look for: sticky, shiny drops on leaves, cars, patios and benches under the tree (honeydew).
General information, not a diagnosis. A certified arborist or your county extension office can confirm.
- Insect
- Maples
- Oaks
- Crape myrtle
- Linden
- Birch
- Cottonwood and willow
Signs to look for
Tick what you see. More ticks make it more likely, but only an on-site look can confirm.
0 of 7 signs ticked. Ticks stay in this browser only.
Season
Mostly spring through early summer when new growth is soft, with some species active again in fall. Populations often crash on their own when hot weather arrives or natural predators build up.
How it spreads
Aphids multiply fast and can fly to nearby plants when a colony gets crowded. They are moved short distances by wind and by ants that protect them. They do not usually kill a healthy mature tree.
Where it is found
Aphids live on trees in every part of the US, and different aphid species favor different trees. Check your state official map; ranges change.
Official sources
What to do
- 1
Look closely first. Honeydew and sooty mold are cosmetic on most mature trees and often need no spray.
- 2
Wash small colonies off young trees and shrubs with a strong spray of water.
- 3
Leave lady beetles, lacewings and other natural predators alone. They often bring a colony under control within weeks.
- 4
Do not spray a broad insecticide on a blooming tree. It can harm bees and kill the predators that help you.
- 5
If a young or high-value tree is badly hit, ask a licensed pro about a targeted product such as insecticidal soap or horticultural oil. Always follow the label.
- 6
Wash honeydew off cars and outdoor furniture. Parking elsewhere for a few weeks is the easy fix.
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
Avoid heavy nitrogen fertilizer, which pushes soft new growth that aphids love. Water young trees during dry spells, plant a mix of species, and keep ants from climbing the trunk only when a pro advises it. Healthy, mixed plantings handle aphids best.
When to call a pro
Call a licensed arborist if leaves are dropping early on a valuable tree year after year, if honeydew is a safety or slip problem on a walkway or business lot, or if you are unsure whether the insect is an aphid or a more serious pest like a scale.
Not sure who to call? Read how to hire a tree service or check is my tree dangerous?
Trees it affects
Usually seen on: Maples, Oaks, Crape myrtle, Linden, Birch, Cottonwood and willow, Pecan and walnut, Tulip poplar.
- Red Maple
- Silver Maple
- Norway Maple
- Pin Oak
- Willow Oak
- Crape Myrtle
- American Linden
- Black Cherry
- River Birch
- Paper Birch
- Tulip Poplar
- Eastern cottonwood
- Weeping Willow
- Black Willow
- Black walnut
- Pecan
See all species in our tree library, or pick a tougher tree with the tree picker.
For tree companies
How to explain aphids to a customer
Aphids are a common spring call, and most of the time the honest answer is that the tree will be fine. Explain that sticky drips and black mold look bad but rarely harm a mature tree, and offer a plan only when the tree is young, stressed or the mess is a real problem. Customers remember the company that did not push an unneeded spray, and they call again when a real problem shows up.
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 is the sticky stuff dripping from my tree?
It is usually honeydew, a sugary liquid that aphids and some other sap-feeding insects leave behind. Look at the underside of leaves above the sticky spot for small soft insects.
Will aphids kill my tree?
Rarely. A healthy mature tree usually shrugs off an aphid outbreak. Young or already stressed trees can be set back more.
What is the black coating on the leaves?
It is sooty mold, a fungus that grows on honeydew. It blocks some light but does not feed on the tree, and it fades once the aphids are gone.
Do I need to spray?
Often no. Natural predators and weather clear many outbreaks. Spraying is mostly for young trees, heavy infestations or places where the mess is a problem.
Why are there ants on my tree?
Ants feed on honeydew and protect aphids from predators. Ants on the trunk are often a clue that aphids or scale insects are feeding above.
Will the aphids come back next year?
Many times they do, because they are common and spread fast. The damage is usually small each year, and good tree care helps the tree handle them.
Can Lirevon diagnose aphids 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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