Q: In a matter of days after planting, most of my columbine leaves had serpentine patterns on them. Some look like they will yellow and drop off the plant. Is this a leaf miner?
A: Anyone who grows columbine, Aquilegia canadensis, will have columbine leaf miner on the plant foliage. In fact, I often see the trails on columbines for sale in nurseries.
The insect adult is a tiny fly. The female lays single eggs at different spots on leaves. When the egg hatches, the larva burrows into the leaf and begins tunneling between the upper and lower surface of the leaf. As the larva grows bigger the serpentine trail becomes wider. In early June the larvae will pupate and drop to the ground to wait for next year’s victims.
Other than the visual disfigurement, columbine leaf miner doesn’t seem to hurt the plant. Columbine itself is usually a short-lived resident of Atlanta-area gardens.
I think the best control is to shear off the foliage immediately after blooms fade, when you can see tiny seed pods. Scatter seed nearby. The original plant may sprout new leaves by mid-summer but if it dies, the seed will sprout to give fresh plants for next spring.