A few days later, look what landed on our driveway! This got me thinking about dragonflies.
Here's what I learned:
- Dragonflies were some of the first winged insects to evolve, some 300 million years ago. Modern dragonflies have wingspans of only two to five inches, but fossil dragonflies have been found with wingspans of up to two feet.
- There are more than 5,000 known species of dragonflies.
- In their larval stage, which can last up to two years, dragonflies are aquatic and eat just about anything—tadpoles, mosquitoes, fish, other insect larvae and even each other.
- At the end of its larval stage, the dragonfly crawls out of the water, then its exoskeleton cracks open and releases the insect. Its four wings come out, and they dry and harden over the next several hours to days.
- Dragonflies are expert fliers. If they can’t fly, they’ll starve because they only eat prey they catch while flying. They catch insects by grabbing them with their feet.
- Dragonflies are a great control on the mosquito population. A single dragonfly can eat 30 to hundreds of mosquitoes per day.
- Some adult dragonflies live for only a few weeks while others live up to a year.
- Nearly all of the dragonfly’s head is eye, so they have incredible vision that encompasses almost every angle except right behind them.
- A dragonfly called the Globe Skinner has the longest migration of any insect—11,000 miles back and forth across the Indian Ocean.
- Hundreds of dragonflies of different species will gather in swarms, either for feeding or migration. Little is known about this behavior, but the Dragonfly Swarm Project is collecting reports on swarms to better understand the behavior. According to the Scientific American swarms are very difficult to study because they are incredibly brief events. You have to be in the right place at the right time to see one and many people will go their entire lives without ever witnessing a swarm.
Facts about dragonflies from smithsonianmag.com and Scientific American