growth on tree

Asked June 5, 2018, 9:10 PM EDT

Found this growing on one of our oak trees near Grayling. Yesterday there was 1, today there are 3. Would like to know what it is and what we should do with it? Is it a fungus of some sort? Is it an insect/ lworm? Is it dangerous? Will it harm the tree? Any information you can give me about it would be appreciated!

Crawford County Michigan

7 Responses

It appears the photo you intended did not upload. Can you please send it again? Thanks!

If this doesn’t work, can I try emailing it to you?

Got them! I'll now assign your question to an MSU Extension expert. Thanks!

Any idea what the things on our oak tree are yet?

They are one of many oak galls. The gall is caused by a minute insect female who laid her eggs in that spot. The infant larvae is providing a temporary home for itself until it matures and then it flies a mate and thence starts the whole cycle once again. By the time you see the gall the time for treatment has passed. Thank you for using the Ask an Expert System. .

So, can we destroy it? If so how? Will destroying it prevent it from spreading????

She’s already abandoned house and home. Once she mates and lays her eggs she’ll die and the new infants will set up housekeeping somewhere else on the same tree or another nearby of the same type of oak. In this càse it won’t hurt to cut off the twig they are on. Should you discover another gall on a larger branch be advised that cutting off the larger branch might do harm to the tree and in this event you’ll scrape the gall off. Good luck.