?Crepemyrtle bark scale? - Ask Extension
In 2022 you had given us helpful information about our declining bird's nest spruce (which is doing great now - thank you!). At the time, you had noti...
Knowledgebase
?Crepemyrtle bark scale? #878625
Asked July 24, 2024, 4:37 PM EDT
In 2022 you had given us helpful information about our declining bird's nest spruce (which is doing great now - thank you!). At the time, you had noticed our crepemyrtle in the photo we sent and advised us to be on the lookout for crepemyrtle bark scale - a new pest in Maryland. Lately, we have noticed black on several branches of our crepemyrtle and a few dead branches that had a lot of black on them. I am sending a photo of the tree and 2 closeups of branches. Does this look like crepemyrtle bark scale or damage done by the spotted lantern fly which we have seen around? Any help you can give us would be greatly appreciated as this tree is an important plant in our landscape. Thank you!
Baltimore County Maryland
Expert Response
We're glad to hear the spruce has recovered nicely. For the crapemyrtle, the close-up photos of the branches show some lichen growth (natural and harmless) and what might be a mild amount of sooty mold darkening the bark. That fungus doesn't infect the plant, but if it's growing on honeydew, the source of that honeydew can be a range of sap-feeding insects. On crapemyrtle, the two insects primarily responsible for producing honeydew would be Crapemyrtle Bark Scale and Crapemyrtle Aphids. Since we don't see any scale in the photos, aphids or any Spotted Lanternfly in the area might be the cause here, if it is indeed sooty mold and not other harmless mold growth.
Although there was concern over the risk when this insect was more new to our area, Spotted Lanternflies have since been observed to not cause any significant damage to home landscape plants, though their honeydew production (when populations are high) can be a nuisance and offensively smelly when large amounts of it ferments, plus may support unappealing outbreaks of heavier sooty mold growth, since honeydew is mostly sugar-water.
If you think you see scale on the main trunk or branches, feel free to share more photos for feedback, but from what we can see, the tree looks good and no scale are visible.
Miri
Although there was concern over the risk when this insect was more new to our area, Spotted Lanternflies have since been observed to not cause any significant damage to home landscape plants, though their honeydew production (when populations are high) can be a nuisance and offensively smelly when large amounts of it ferments, plus may support unappealing outbreaks of heavier sooty mold growth, since honeydew is mostly sugar-water.
If you think you see scale on the main trunk or branches, feel free to share more photos for feedback, but from what we can see, the tree looks good and no scale are visible.
Miri
Thank you for your reply, Miri. I'm sending a photo of a few small white cottony areas on the trunk. I have not seen any insects on the crepemyrtle just a few dead branches covered in black and live branches with a bit of black on them. The black is not something that I have seen on the crepemyrtle before. The leaves look fine. Maybe just keep a watch to see if more branches die? Thank you!
Thank you for the additional photo. It's hard to tell if the white objects are scale or something else. Usually, scale are much more numerous and tend to be clustered together, not scattered as they appear here. You can prod at them and try to flip some over to see if they are rosy-red or pinkish underneath. If these are Crapemyrtle Bark Scale but the population is this low throughout the tree, than no action needs to be taken, and any honeydew that sooty mold may be growing on is likely produced by something else, like perhaps the aphids.
If any branches or twigs have been leafless all summer, then they are presumed dead and should be pruned off, though the reasons for dieback are hard to determine since there can be many causes, including temperature fluctuations during a prior winter.
Miri
If any branches or twigs have been leafless all summer, then they are presumed dead and should be pruned off, though the reasons for dieback are hard to determine since there can be many causes, including temperature fluctuations during a prior winter.
Miri
Thank you!
