Pests on my birch tree

Asked May 8, 2019, 10:18 AM EDT

Our birch tree has caterpillars, the leaves have some kind of eggs growing and a few brown sack like growths dangling on branches. I cut off the caterpillar invested branches and the growth but can you tell me what they are and what to do about the stuff on the leaves. Attached pictures. Thank you in advance for your help.

St. Mary's County Maryland leaf galls trees pest insects and mites

1 Response

The insects in your first photo are called dusky birch sawflies. You did the right thing by pruning out the infested branches. Here is more information about sawflies.
https://extension.umd.edu/hgic/topics/sawflies-trees-and-shrubs

The brown object looks like a bagworm case. These too can be pruned out manually. https://extension.umd.edu/hgic/topics/bagworms-trees-and-shrubs

The bumps on the leaf are galls. These structures are a response by the plant to insects or mites (usually) or bacteria or fungi. It is not unusual to see them in shade trees at this time of year. They do not seriously affect the overall health of trees. No treatment is recommended.
https://extension.umd.edu/hgic/topics/shade-tree-galls

Christa