Brown oak tree droppings

Asked July 9, 2019, 9:43 AM EDT

We have lots of small brown balls dropping from our oak trees which I think are waste from caterpillars in the trees. They turn green & slippery when wet & hard to remove when dry and firmly attached to our deck & outside furniture. Lots on the bottom of shoes when walking under the trees. How long will these last & is there anything we should do to control them? I don’t remember them being this bad before in Hubbard Lake!

Alcona County Michigan

3 Responses


My first guess is they are gypsy moth caterpillars. I think they should be nearly done by now. So possibly another week or so before they stop feeding and enter the cocoon stage.


So there’s nothing we should do to control them? Will they destroy the trees - they’ve already eaten a lot of leaves.

If the trees aren't too big to treat yourself, then sprays containing Sevin or Ortho Bug-B-Gon will kill them now. If not, then it will be very expensive to hire someone to spray them.