The Two Worlds of the Odonata (Dragonflies and Damselflies)

The pond is dotted with water lilies and ringed by purple iris. A thin twitch of bright blue catches my peripheral vision. Now it's motionless, a dashed line, blue and black, balanced on an iris leaf. Wings are folded along its back and the head is wide, with eyes on the sides. It's a common bluet, or common blue damselfly.

Now that my eyes are tuned to the small insects, I start to see more. A thicker, red insect lands on a small sign in the pond. It holds its wings out from its sides, rather than folding them down its back.  The wings look like fine mesh. This is a cardinal meadowhawk, a type of dragonfly.

Its match, but in blue rather than red, lands on a leaf. It's a blue dasher, or blue darter.

Dragonflies and damselflies comprise the order Odonata, and have been around for about 350 million years. Dragonflies have evolved incredible agility in flight, with the ability to fly backward or upside down, and to make sudden changes of direction and speed. Odonata have also evolved advanced vision. They can see 360° around them, and see colors in much greater detail than we humans can. Humans have three kinds of opsins in our eyes that detect green, red and blue; the colors we see are mixes of different amounts of these three colors. Dragonflies have eleven kinds of opsins—what does the world look like to them?! They can even see ultraviolet light. They also have three small eyes called ocelli that are specialized for detecting extremely fast movements.

Odonata hatch from eggs laid in or near water. They then live most of their lives underwater as nymphs, which look kind of like narrow beetles. As nymphs, they hunt other aquatic insects, as well as tadpoles, and even small fish. Dragonfly nymphs seem like science fiction creatures: they have mouthparts like a lower jaw that can shoot out to snare their prey, and they can blast water out of their anus for a quick burst of movement.

A nymph may live eight or nine months, or for some species several years, before it transforms into an adult dragonfly or damselfly, usually emerging in the spring or early summer. The zipping lines of blue, red, brown, or green above ponds and streams is a sign of summer. As adults, dragonflies and damselflies hunt bugs in the air, often above the same pond or stream where they lives as nymphs.

I like imagining that experience. A dragonfly spends most of its life immersed in water, the surface a barrier it might never breach. The water is its world, its universe. Then, a change, a transformation, and it leaves the water. It takes to the air. What would it feel like to look down on your old world, see its surface, but never enter that world again?

LINKS:
UC Botanical Garden where I saw these Odonata
Odonata Central species accounts:
       Common bluet
       Blue dasher
       Cardinal meadowhawk
Science Magazine article about dragonfly flight
Western Odonata facebook group