Unpacking the Nature Basket IV

Not all nurseries are painted pink or blue.

Well, I'm almost done unpacking the Nature Basket. These are the last three items I'm bringing out for discussion. Because I found these so very close to home, they are a good reminder to keep a sharp eye out when working around your house. I found the specimen on the upper left under my porch railing, the one on the upper right above my garage door, and the one on the bottom in my front garden.

Even though they look very different, they all have the same function. All three are nurseries for the eggs and larvae of insect species. The two on the top are wasp nests, each made by a different species of wasp. The one on the bottom is a goldenrod gall, formed when a goldenrod gall fly lays its egg in a goldenrod stem.

Wasps were the very first paper-makers. Wasps fly about to find sources of wood and chew off the wood fibers. I have watched one wasp, probably the one that made the nest in the photo, as it chewed the wood off clothespins on my clothesline. It was so quiet that day I could hear it chewing! The wasp then took the wood, mixed it with wasp spit to form pulp, and then spread it into the thin layers to form the nest. If you look closely at a paper wasp's nest, you may see that the paper is often arranged in multicolored bands. The differently colored bands originated with different sources of wood! After completing a paper nests, the mother wasps lay their eggs in the chambered cells. Wasps guard their nests, so don't collect any wasp nests until the deep-freeze of winter, when you can be sure they are abandoned.

The tiny goldenrod gall fly, which is very common but rarely seen, does not guard her young. She inserts her egg into the stem of a goldenrod and flies off. The goldenrod reacts to this intrusion by swelling into the gall shape you see in the photo above. In this particular sample, you can see two galls, one above the other. The uppermost gall is almost always smaller than the lower. The gall acts as a nursery where the young overwinter. Inside, the egg hatches and the larva excavate a tunnel to the outside, leaving the thinnest flap of tissue. Then they pupate and change into an adult gallfly. The gallfly is able to leave the gall only because the larvae excavated an escape hatch before metamorphosis. If you look closely you can see the tiny hole through which the gall fly escaped. It is directly above the letter "t" in "painted" and is on the lower third of the gall.