Trees - Ask Extension
I have a maple tree that shedding small droplets of sap all over my deck in my car. Any idea what it could be? I’m thinking it’s some kind of a bu...
Knowledgebase
Trees #931512
Asked May 12, 2026, 8:29 PM EDT
I have a maple tree that shedding small droplets of sap all over my deck in my car. Any idea what it could be? I’m thinking it’s some kind of a bug.
Oakland County Michigan
Expert Response
Hello
There are a number of insects that can feed on maple trees and exude what is known as “honeydew“. The sticky liquid is a nuisance, of course. In spring, most commonly it is a problem with aphids.
More concerning is if the tree has spotted lanternfly nymphs feeding.
Please take a close look at your tree to see if you can see which insects might be present.( pictures below in the bulletins linked)
If the tree has some branches within reach closely examine them for bumps or tiny, fluffy, white clumps along the stems or on the leaves. Be sure to check the underside of leaves, which is typically where insects will hide while feeding. Look for 1/4 inch black insects with white spots as well.
If the tree is a little too high to reach a branch for close examination, try taking a pair of binoculars and focusing on a branch and the underside of leaves.
Compare what you see to the bulletins below to see if you can find a match. You may need to hire a certified arborist to examine your tree to determine which insect is feeding. Treating with insecticides is usually the ladt option, since treatment can kill off natural predators and make the aphid problem worse.
Treating insects on trees requires correctly identifying which insect is present, precise timing, and the use of the correct insecticide, plus equipment powerful enough to reach all the branches, including the top, to apply insecticide with good coverage.
Spring insect pests on maple-
https://blogs.k-state.edu/kansasbugs/2020/06/19/woolly-aphids-on-maple-trees/
https://cals.cornell.edu/integrated-pest-management/outreach-education/whats-bugging-you/spotted-lanternfly/spotted-lanternfly-biology-and-lifecycle
This bulletin shows a number of sap feeders on maple, most of these are not yet actively feeding. https://woodlandstewards.osu.edu/sites/woodlands/files/imce/MAPLE_toolkit_insects%26mites_250717.pdf
If you can’t find the insects yourself and provide us with some clear pictures for identification, you could hire a certified arborist to come on site. These professionals are trained, have passed certification and can identify and treat pests and diseases of trees and shrubs. You can search your area by zip code under the “Find an Arborist” tab here- https://www.asm-isa.org/
There are a number of insects that can feed on maple trees and exude what is known as “honeydew“. The sticky liquid is a nuisance, of course. In spring, most commonly it is a problem with aphids.
More concerning is if the tree has spotted lanternfly nymphs feeding.
Please take a close look at your tree to see if you can see which insects might be present.( pictures below in the bulletins linked)
If the tree has some branches within reach closely examine them for bumps or tiny, fluffy, white clumps along the stems or on the leaves. Be sure to check the underside of leaves, which is typically where insects will hide while feeding. Look for 1/4 inch black insects with white spots as well.
If the tree is a little too high to reach a branch for close examination, try taking a pair of binoculars and focusing on a branch and the underside of leaves.
Compare what you see to the bulletins below to see if you can find a match. You may need to hire a certified arborist to examine your tree to determine which insect is feeding. Treating with insecticides is usually the ladt option, since treatment can kill off natural predators and make the aphid problem worse.
Treating insects on trees requires correctly identifying which insect is present, precise timing, and the use of the correct insecticide, plus equipment powerful enough to reach all the branches, including the top, to apply insecticide with good coverage.
Spring insect pests on maple-
https://blogs.k-state.edu/kansasbugs/2020/06/19/woolly-aphids-on-maple-trees/
https://cals.cornell.edu/integrated-pest-management/outreach-education/whats-bugging-you/spotted-lanternfly/spotted-lanternfly-biology-and-lifecycle
This bulletin shows a number of sap feeders on maple, most of these are not yet actively feeding. https://woodlandstewards.osu.edu/sites/woodlands/files/imce/MAPLE_toolkit_insects%26mites_250717.pdf
If you can’t find the insects yourself and provide us with some clear pictures for identification, you could hire a certified arborist to come on site. These professionals are trained, have passed certification and can identify and treat pests and diseases of trees and shrubs. You can search your area by zip code under the “Find an Arborist” tab here- https://www.asm-isa.org/
Also, if you find spotted lanternfly nymphs, please let me know. This new invasive insect may need to be reported MISN, Michigan Invasive Species Network. Thank you.
Sorry for the multiple updates, here is another bulletin with a clear picture of the spotted lanternfly black nymphs with white spots, that you might find on your tree. https://www.canr.msu.edu/ipm/uploads/files/SLF-Homeowners-Guide-E3534-Final.pdf
I hope this is not the insect affecting your tree.
Regards,
Laura
I hope this is not the insect affecting your tree.
Regards,
Laura
