Stalking Dragonflies: State Entomologist Leads The Way

By Dottie Evans

You can observe an awful lot just by watching.

––Yogi Berra

When it comes to catching dragonflies or holding a live one by its transparent wings in order to get a better look at its bug-eyed face, this is what most people would say to Connecticut State Entomologist Mike Thomas:

“You first!”

Not that most people aren’t curious or respectful of these ancient-seeming insects, it is just that dragonflies seem rather alien. Like creatures left over from the Cretaceous. A bit too primitive and predatory-looking for comfort.

Nevertheless, the 50 or so individuals who showed up Sunday morning, August 24, for a program on dragonflies at the Bent of the River Audubon Center in Southbury had come to see the real thing and to learn from the expert. Several shared what they already knew.

“Dragonflies can hover like a helicopter,” said a little boy.

“Or they can perch and sit very still like a hawk waiting for its dinner,” said another.

“They can also zoom and zigzag across a field, or over a still pond,” a young man said, as the group set out on the meadow trail. The morning was sunny, warm, and clear with a light breeze.

To biologists like Mike Thomas, a dragonfly is more than a creature of great beauty. It is a highly developed insect worthy of study that can act as a barometer of the environmental health of a local ecosystem. This is because where dragonflies flourish, a thriving food chain of smaller insects must also exist, either on the wing or floating as larvae on a body of clean water.

Just knowing where a dragonfly likes to hang out is something the state entomologist cannot resist telling about, and the names of the six dragonfly families have a certain exotic appeal. They are the darners, club tails, spike tails, cruisers, skimmers, and emeralds.

“On cool mornings, walk along the edge of a meadow and you’ll scare a few out of their hiding places. They like to spend the night sitting in a field. As you walk by, you’ll flush them out,” Mr Thomas said.

As he and a few volunteer helpers headed out with long nets to snag some specimens, they carried small, clear plastic cups with lids, to temporarily encase the insects while the group observed them.

Mr Thomas provided a steady stream of dragonfly lore to accompany the hunt.

“Did you know you can hold a dragonfly by its wings, carefully, and not damage it? It’s not the same with butterflies because their wings have scales which will come off in your hand.”

“Some of the species live 90 percent of their lives, or up to four years, in the water. Then they emerge as adults for just a short time, lay eggs, and die.”

“Their wings get darker with age.”

“You can sex a dragonfly by looking at its second segment. Males have claspers, females don’t.”

“Dragonflies are attracted by white, so don’t be surprised if one lands on your shirt.”

“If you wet your finger with saliva, a dragonfly might crawl on. He’s attracted by the salt and the moisture.”

“Their colors change according to the temperature. If it’s cool, the cells don’t scatter as much light. The best temperature is between 80 and 85 degrees.”

“Dragonflies may hunt in swarms. It’s not unusual to see 50 green darners [the most common species] at one time in one feeding group in the late afternoon, zooming in on insects.”

“Dragonflies migrate. But it’s a one-way process. They might fly to South Carolina or Florida and lay eggs. The next generation might fly north again.”

As he led the group around the lower field, Mr Thomas made sure people were able to examine any dragonflies that were netted, as well as any other insects and sundry creatures the group encountered, such as tiny frogs, moths, butterflies, and an early woolly bear caterpillar.

Audubon Education Director Ellen Turner made sure the live exhibits got passed around, and helped ensure that each child who wanted to use a net got a turn.

“It’s amazing what the children see, that we adults often miss,” she said.

According to Mr Thomas, there are insects enough for all.

“We’ve got 2,400 species of moths, 119 species of butterflies, and 148 species of dragonflies –– just in the state of Connecticut alone.”