Caught in the Act – Dragonfly Emergence Arrested
No, I’m not writing about any burglary or deceitful thing someone was hoping to keep secret. I want to share a picture of a dragonfly emerging out of its larval exoskeleton.
Dragonfly adult died while emerging from nymphal encasement
Nyaids, or the larval stage, of dragonflies are aquatic. They go through 10 to 15 instars (or molts) before reaching the point at which the land-dwelling adult emerges. Depending on the species of dragonfly it may live a number of weeks or up to five years in this nymph stage. During this time, the dragonfly breathes through gills in its abdomen and preys upon insects, tadpoles, or whatever it can manage in its calm water habitat.
When it is time, the nymph will crawl out of the water onto the leaf of an emerging plant. The back of the exoskeleton will split as it sucks in air. Soon the adult will crawl out. After a bit of time getting strength to its legs, it will pull itself free of its “former self” and spend a few hours pumping blood throughout its body. Everything gets bigger, even its eyes. It is very vulnerable at this time and hopefully it is sufficiently hidden from predators. Eventually its transparent wings are fully unfurled and it will fly off. The next, and last 2 or so months of its life, are spent seeking a mate and making the next generation. Dragonflies do not over-winter as adults. They over-winter as nymphs in the water.
I did not accomplish this little find myself. I was teaching a class of 4th graders from Glenwood School in Springfield, MA and Alex excitedly brought this to me during our pond study. He didn’t know what it was, but soon learned. Those kids can surely find some wonderful stuff!
This fellow perhaps got caught in mid-act by a cold snap. Just a conjecture, but reasonable since oftentimes it is evening when nymphs crawl up out of their pond to begin the transformation to adulthood.