Garden Pests and Diseases: What is this on my bee balm stems?, 3 by smartblonde

smartblonde wrote:
HELP! Can you tell me what this is on many of my bee balm stems? I\'ve never seen it before. I live in Delaware. The bee balm plants are 5+ years old, and were growing among black-eyed Susans, orange day lilies, hosta, and wild ferns; all of the black-eyed Susans have died off, but I was told they were a variety with about a 3 year life span. Actually, all the root balls of the Susans had holes in them and looked dried out (nematodes?). The garden bed faces the north. I have already pulled out around 20 Monarda plants. We have used insecticide for Japanese beetles last year but no other chemicals. I\'ve read about this products: [HYPERLINK@www.growerstrust.com]
and don\'t know if I should try it or add something like beneficial nematodes.
The first photo was last summer; the others are from yesterday.
ANY ADVICE MUCH APPRECIATED!