During this past week Dave and I witnessed something amazing. We watched dragonflies metamorphose. This means they changed. Have you ever seen a dragonfly? Dragonflies are large insects that fly. They have long bodies and two sets of large wings. They eat other insects and they fly really fast. They don’t spend much of their lives in their adult form though. Most of a dragonfly’s life is spent in the water.
Have you seen metamorphosis before– like a caterpillar turning into a butterfly? What was it like?
While camped on Horseshoe Lake, we were about to launch our canoe when we noticed several dark shapes attached to it. Upon first glance we could see that the shapes were dragonflies. All the dragonflies were latched onto something. Upon closer inspection, we realized that these dragonflies had just undergone metamorphosis, they had emerged from their nymph exoskeletons and were hanging off of our canoes, drying out and stretching their wings. Did you know that insects have exoskeletons? That means they have a hard covering over their bodies, unlike us humans who have our skeletons inside our bodies.
Can you think of any other animals that have exoskeletons? What do you think it would be like to have an exoskeleton?
Over the next few days we saw nymphs crawling around on the forest floor. They had just crawled out of the lake. A dragonfly spends most of its life in the nymph form, creeping along on the lake bottom. Many species of dragonfly spend several years living as nymphs. These dragonfly nymphs are large– they would take up most of the palm of your hand. Someone once told me they look like “little monsters”. I think that they would play the part of scary alien invaders in a movie well if they were closer in size to us.
We followed a couple nymphs to see where they stopped and what they would do next. We found that they settle in a spot with a slight overhang and firmly latch on with their legs, so that their new bodies can take advantage of gravity. This is why the side of our overturned canoe was a good spot. We’ve also spotted them on the trunks of cedar trees, balsam branches, rocks, and the guy lines our tent.
We saw some movement and looked closely to see the dragonfly’s head pop out. The head and legs of the adult dragonfly emerged. It shifted position a little to get in the optimal spot to allow its wings to hang down. The wings were barely noticeable at first, plastered to its body. Slowly they appeared to grow. The dragonfly’s abdomen appeared to grow too, because it emerged wide and short, but slowly lengthened and narrowed. Eventually the dragonfly spread its wings for some final drying in the sun and breeze. Then the dragonfly fluttered its wings and flew away. All that was left was the exoskeleton of the nymph.
What stage of a dragonfly’s lifecycle would you like to experience? Why?
We were lucky enough to see this metamorphosis happen many times over the course of two days. I lost count of how many dragonflies we saw change from nymph to adult. I am especially glad that there are many adult dragonflies flying around now, because they eat insects– including some insects that bite people, like black flies and mosquitoes. Of course, some of the dragonflies don’t live very long in their adult form, because some birds like to eat them.
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