What is eating my river burtch? How do I get them to stop
Thank you for attaching the image of the insect on your birch. It is a dusky birch sawfly, Croesus latitarsus.
Even though it resembles a caterpillar, the same chemicals don’t necessarily work. But, if they’re within reach, this simple remedy always works: Flick them into soapy water. Some folks go so far as to cut them in half or stomping.
Birch sawflies have 2 generations each year. So, this is the first generation, but another is due in August or so, when you’ll need to reactivate your search-and-destroy routine.See http://bygl.osu.edu/bygl_archive2015/content/dusky-birch-sawfly-0
Thank you Jean! Once again OSE is very helpful.