The Goldenrod Gall Fly is a tiny little creature that is flying around all the time, but we don't often notice it. It lays an egg on the stem of the goldenrod plant and that egg becomes a little white maggot. The maggot burrows into the stem of the plant causing the plant to grow a tumor like lump called a gall. The maggot lives inside this plant eating and eating until it finally turns into a hard brown pupa. About two weeks later, that pupa opens up and a little fly crawls out. The fly mates, lays an egg on a goldenrod stem and the cycle starts anew.
We spent some time looking carefully at these galls - drawing them and making observations. Then we generated a list of questions. The most popular question was, "What is inside the gall?" So we cut them open to find out. The kids were amazed (and a little creeped out) to find a small wiggly worm inside. Now their question was, "How did it get in there?" After some discussion, I shared with them the biology of the Goldenrod Gall Fly. We took a little walk to a field near the school where we found more galls.
Each student will be writing a report on the Goldenrod Gall Fly. Check them out in the hallway by our classroom later this week!