Nursing oak tree

Asked August 11, 2017, 10:45 AM EDT

This below latched on, or grew on it. I don't know what it is. Asked several people already.

Bronx County New York oak galls beaked twig gall

1 Response

This looks like a gall, possibly a cluster of beaked twig galls. Entymologist Leslie Mertz provides this information and more at the link below: "Galls start when a female insect lays an egg in some actively growing part of a plant, and something in the saliva or other fluids of that female or in her developing offspring prompts the plant tissue to grow into a gall. The young insect lives inside the gall, which can provide both shelter and a food source, and when it gets big enough — usually when it becomes an adult — the insect makes its way out." More info here: https://entomologytoday.org/2015/06/11/galls-insects-behind-the-weird-growths-on-plants/

If you have only a minor infestation you won't need to take any corrective measures. If you notice them on more than one branch you can prune the affected branches off and any affected leaves, making sure to remove these from your yard. It's unlikely that you will need to do anything more, but this link will provide you with additional information:
http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/other/galls/gouty-horned-and-other-twig-galls.aspx