Maple Tree Infestation with Spotted Lantern Flies - Ask Extension
MG - I have a mature Maple tree with 2 main vertical trunks. One trunk was removed around 8 years ago. The remaining cut line from the removal never ...
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Maple Tree Infestation with Spotted Lantern Flies #947557
Asked October 23, 2026, 11:02 AM EDT
MG - I have a mature Maple tree with 2 main vertical trunks. One trunk was removed around 8 years ago. The remaining cut line from the removal never healed completely resulting in the portion of the trunk from cut to ground has been rotting, growing fungus. attracting insects. The other tree trunk has showed signs of stress in the last year or so. Recently the entire maple tree has thousands and thousands of spotted lantern flies over all trunk and branch area. The leaves are stating to get black spots. It is not feasible to get up tree and scape all the egg laying areas. If I do nothing, what is the impact of thousands and thousands of lantern flies being hatched in my yard? I do not think my garden and landscaping will be happy. Since the tree appears to be stressed and the remaining bottom trunk rotting, is a good solution simply to cut and remove the tree and roots? Please advise. I live in southern Anne Arrundel County. There were no lantern flies here 2 years ago, now they are everywhere.
Anne Arundel County Maryland
Expert Response
Spotted Lanternfly is present across Maryland (even if portions of certain counties or neighborhoods haven't seen many yet) and is present in over a dozen states. While removing individuals by squishing egg masses and nymphs/adults may help to slow an infestation where the insects are brand-new to the area, in all areas where the population is well-established, it won't have much impact. Even if egg masses are found and destroyed in winter, a significant portion of them will be laid out of sight and out of reach.
Fortunately, these insects do not cause notable harm to home landscape plants (grape vines being a possible exception), even when they are abundant. High numbers of the adults feeding on a single tree might weaken it, but it would only be fatal if that tree was already suffering from other overlapping problems. In this situation, the greater risk to the maple is definitely the ongoing wood decay from the old pruning cut.
Trees can compartmentalize decay so it doesn't spread internally, but a certified arborist would have to examine the tree to determine how intact or compromised the remaining trunk currently is, since that compartmentalization process doesn't always work. There is no treatment or cure for wood decay damage, and while trees sometimes can live for decades with internal decay (the innermost wood in a tree trunk is naturally already dead wood, so its loss isn't a major health risk; it's the layer of tissue not far under the bark that is alive and supplying the canopy with moisture and nutrients when a tree trunk becomes hollow), it's hard to predict when they will die or fall apart.
Any tree health concerns should be evaluated by an arborist or licensed tree expert, especially since they need to assess the situation in person. Some tree companies may have tools that can scan the wood for cavities from decay to see how far it has progressed into wood that looks intact from the outside. If the tree is a fall risk, the arborist will almost certainly recommend that it be removed unless its falling will not damage property or harm people. Removing the tree won't keep the lanternflies from sticking around or reappearing next year, but they would probably not be as concentrated around a single plant.
Miri
Fortunately, these insects do not cause notable harm to home landscape plants (grape vines being a possible exception), even when they are abundant. High numbers of the adults feeding on a single tree might weaken it, but it would only be fatal if that tree was already suffering from other overlapping problems. In this situation, the greater risk to the maple is definitely the ongoing wood decay from the old pruning cut.
Trees can compartmentalize decay so it doesn't spread internally, but a certified arborist would have to examine the tree to determine how intact or compromised the remaining trunk currently is, since that compartmentalization process doesn't always work. There is no treatment or cure for wood decay damage, and while trees sometimes can live for decades with internal decay (the innermost wood in a tree trunk is naturally already dead wood, so its loss isn't a major health risk; it's the layer of tissue not far under the bark that is alive and supplying the canopy with moisture and nutrients when a tree trunk becomes hollow), it's hard to predict when they will die or fall apart.
Any tree health concerns should be evaluated by an arborist or licensed tree expert, especially since they need to assess the situation in person. Some tree companies may have tools that can scan the wood for cavities from decay to see how far it has progressed into wood that looks intact from the outside. If the tree is a fall risk, the arborist will almost certainly recommend that it be removed unless its falling will not damage property or harm people. Removing the tree won't keep the lanternflies from sticking around or reappearing next year, but they would probably not be as concentrated around a single plant.
Miri
