Goldenrod gall, Bell

I was on the trail this afternoon through an old meadow that is giving way to weeds and small shrubs, but because nothing is beginning to leaf out, it's easy to see last year's action. I didn't manage to spot any Praying Mantis egg cases, but on many of the old goldenrod stalks, I noticed an egg-like swelling on the upper part of the stem. This is a gall, a kind of plant tumor induced by the bite or sting of a small insect. More than 50 species trigger these bumps in various parts of Solidago species, but one of the most common annoyers is the Goldenrod Gall Fly. Eurosta solidaginis lays a single egg in the stem, and the egg-laying action, along with the development of the larva, induces the plant to make a round growth that serves as a nursery and food source for the young fly, which has a remarkable cold tolerance. The youngster is still in a kind of natural-antifreeze-protected stupor, but soon enough, as the temperature warms, the larva will emerge from its hangover and turn into a pupa, before it metamorphoses into an adult and emerges from a tunnel that the larva cut earlier. I'll be waiting, camera ready.