Cool critters: Official state insect of Washington is a ‘mosquito hawk’

Emerald green with slashes of blue, the green darner dragonfly is among the biggest and fastest of the dragonfly species in North America. You’ve probably seen them darting around bodies of water in the Inland Northwest. Now that it’s September, many of these insects will soon depart on an epic migration loop that researchers uncovered only several years ago.

They also bear the distinction of being the official state insect of Washington.

A voracious predator of mosquitoes, the green darner dragonfly is named for its long, thin abdomen that resembles a darning needle. The insect’s two pairs of wings are so shimmery that even Tinker Bell would look twice.

“It is a beautiful and showy insect,” said entomologist Richard Zack of Washington State University.

And Zack would know. In 1997, he served as insect consultant to students at Crestwood Elementary in Kent, Wash., helping them identify “good bug” candidates for the state’s official insect. To be considered, candidate insects had to be native to Washington state, beneficial to the environment and not harmful to people or animals.

“With much work, and with the participation of students from schools throughout the state, they succeeded in having the green darner dragonfly designated,” said Zack, who attended the bill-signing ceremony at Crestwood school.

With the stroke of Gov. Gary Locke’s pen, the green darner dragonfly became the Evergreen State’s newest symbol – joining the apple as its state fruit and the willow goldfinch as its bird.

According to the 1997 bill, “the common green darner dragonfly, also known as the ‘mosquito hawk,’ is a beneficial contributor to our ecosystem.”

Mosquito hawk? There’s a good reason for that nickname. Not only does it acknowledge the staggering number of mosquitoes the green darner devours, but it also recognizes that the insect, like the hawk, is both beautiful and deadly.

Unlike the hawk, however, the green darner has no sharp talons or beak. And unlike deadly mammals, it has no slashing teeth or claws. And yet, it may be the most successful hunter in the animal kingdom, according to a growing body of research.

How does a pretty, dainty-looking insect with a brain the size of a rice grain do it?

Green darners, like all dragonfly species, hunt their prey in midair with astounding speed and agility. Each wing is individually powered, giving the insect the ability to zip forward, backward and sideways and perform hairpin turns. It can also go up and down like a helicopter, do backflips and stop instantly.

An extraordinary vision system accounts for the dragonfly’s hunting prowess as well, according to a string of recent studies. Two huge compound eyes and three simple eyes cover most of the insect’s head, providing a vision range of nearly 360 degrees. What’s more, each compound eye contains thousands of telescopic lenses. The better to see you with, Mr. Mosquito.

Obviously, since the green darner dragonfly became the state’s official insect nearly years 30 ago, scientists have made some intriguing discoveries about dragonflies.

Another interesting discovery? Green darners, a bit like monarch butterflies, are migratory marathoners that fly up and down the continent each year.

Many of the darners you see skimming along water or grasses will soon head south, buzzing along at roughly 10 mph and covering as much as 90 miles each day. Once settled in the southern U.S., Mexico or the Caribbean, they’ll produce offspring, according to a 2018 study published in the journal Biology Letters. Then, that offspring will produce the generation that migrates north next spring.

This means that green darner dragonflies “repeat a journey their great grandparents made,” researchers concluded in the study.

And they do so with helmet-like eyes and the tiny beats of glittery, 2-inch wings.