Maple tree

Question

I live in eastern MA. We have a mature maple tree in the backyard the leaves of which turn yellow (not orange)in the fall. For the last few years it has been inflicted with ‘winter moth'(I am told by Trugreen guys) their caterpillars eat the tender leaves in the spring and the leaves have black/brown splotches in the summer & fall. The Trugreen guys spray it every year 4 times with some chemical but the problem is not solved.

My question to you is that if I get all the branches (with leaves) cut , leaving only the limbs this fall, will the tree survive? How long till leaves come back- approx.1 or 2 or more spring cycles? I understand it may be years to get a proper canopy of leaves.I want to get rid of the ugly leaves and the disease but am afraid to loose the only tree I have (it is about 40’high and a canopy of 30-35’wide)

Answer 1

Maybe it’s just me, but I don’t trust lawncare companies with my trees. Their interest is in selling you something. Black “tar” spots on maples is a very common issue but fortunately, it is only a cosmetic problem, meaning it doesn’t affect the tree’s health. I is a fungal disease, not caterpillars or “winter moth”. No treatment is necessary except to clean up and dispose of infected, tar spotty, leaves. The fungus overwinters on the leaves and when spring winds pick up, it makes its way back to the tree canopy. Read here: http://www.mortonarb.org/trees-plants/tree-and-plant-advice/help-diseases/tar-spot-maple-rhytisma-spp

Answer 2

The spring feeding damage is characteristic of winter moth but I am not sure why winter moths would cause black or brown splotches on leaves later in the year. That could be a separate problem like a maple leaf spot. Most of those are not harmful to the tree.

I don’t think cutting the infested branches will help your tree and can only hurt it. The caterpillars pupate in the soil and then the adult moths can move from one tree to another. The eggs are laid during late fall and winter on the trunk as well as the branches, so you couldn’t remove them all by cutting off branches.

See these articles for more treatment options. Since the chemical spray is not working, the insects may have become resistant to it, so it’s probably best to try biological and/or physical controls, like Bacillus thuringienses or physical barriers.

https://ag.umass.edu/fact-sheets/winter-moth-identification-management
https://ag.umass.edu/fact-sheets/winter-moth-overview
http://web.uri.edu/ipm/2015/03/winter-moth-2015/