Caterpillar eating columnar dawyck beech leaves – what can I do?


I have twelve beech trees lining my property. This morning I noticed holes in the leaves, and after investigation I saw very small worm or caterpillars. They are approximately 10 feet apart and approximately 17 feet tall. What can I do to get rid of them? Your advise will be greatly appreciated


Thank you for contacting the Toronto Master Gardeners. I can’t be sure from your picture which caterpillar this is, and it’s important to know exactly since the treatment required depends on the caterpillar. Have the caterpillars on your beech created tents or webbing ? I think this could be the caterpillars of Gypsy Moths which don’t have tents or webbing, which emerge in the spring and one of the trees they feast on is beech. Last year was a bad year in parts of Ontario for these pests and this year is looking similar. You could send us a very clear close-up picture to have us confirm what it is, or collect a few and take them to a nursery for identification, or identify it yourself. Here are a couple of links to information about Gypsy Moth caterpillars and a few other similar common caterpillars, including how to treat for them :

If what you have is not any of the caterpillars in the above links, here are pictures of many of the caterpillars in Ontario :

Gypsy Moth caterpillars in particular can have a significant negative impact by defoliating trees. Other caterpillars can also be very damaging. Since you have so many large beech trees that are either infested or could be, you might want to consider contacting a certified arborist to take a look and recommend treatment. Landscape Ontario has a list or certified arborists on their website :

Best of luck with your trees !