Oak leaves detroyed - Ask Extension
We have something in our neighborhood devastating our oak trees. The leaves appear to be eaten, some are curled and brown. Some have flesh and veins m...
Knowledgebase
Oak leaves detroyed #646003
Asked June 04, 2020, 2:28 PM EDT
We have something in our neighborhood devastating our oak trees. The leaves appear to be eaten, some are curled and brown. Some have flesh and veins missing and others just holes in them. Found a small white bug on one of the trees and small green worms. There are lots of “webs” on the trees.
We are actually in Washtenaw county, just north of Chelsea.
We are actually in Washtenaw county, just north of Chelsea.
Livingston County Michigan
Expert Response
Hello
There are many pests of oak trees which cause leaf damage, and it is not a life-threatening issue. I am attaching some references that show some of the possibilities. Oak shothole leafminer appears to be one of the pests in your picture, and possibly some anthracnose causing the browning on the leaves. Anthracnose has also been occurring on maples this spring
There are a number caterpillars that feed on Oak leaves leaving little but the veins behind. Also this year in certain parts of Michigan we are seeing some gypsy moth caterpillar feeding. Any of these could be what you have on your oak, although the white spot and the green caterpillar are not gypsy moth. Here are some of the common caterpillars found on oaks-
And you can monitor for gypsy moth and scape off and destroy egg cases later if you see them:
For exact identification you may send sample insects to MSU Entomologist Howard Russell, Diagnostic Services 116 Integrated Plant Systems, Michigan State University, East Lansing MI 48824-1311 To send specimens, place 6 or so undamaged insects in a small leak proof bottle filled with white vinegar, then packaged safely for mailing, including your email contact info and on which plants you found the insects.
If you have any very young oaks, say under 15 feet tall that are being damaged, keep these oaks well watered during dry times this summer to help them recover from the damage. Keeping fallen leaves and twigs raked up and bagged will help reduce some of the pests from over wintering.
