I found a bug on my columbines today. There were 3-4 flowers that had been eaten quite significantly on the edges of the outer (fuchsia) petals, and the stamens were eaten right off. I took a picture of the culprit, which you can see at my Facebook page (https://www.facebook.com/phylogenyart). It looked like some sort of caterpillar that’s greenish gray with segment lines along the body, no fuzz, and had a pronged tail to hold on to one petal while eating through the center of the flower (how I found him). So, my question is whether this bug is a bad one or a good one? I planted the columbines (and sedum, and coneflowers too) to attract pollinators, and would love for this to be a caterpillar for some lovely butterfly, but I’m not sure whether it’s a pest that I’ve unknowingly attracted to my garden.
It looks like a columbine sawfly;
http://www.extension.umn.edu/garden/insects/find/be-on-the-watch-for-columbine-sawfly/
Spray it with a good contact killer like insecticidal soap. That will kill the sawfly larvae but won’t harm the pollinators like the bees and butterflies.