Sunday, August 1, 2021

Nature: Double-ringed pennants, other dragonflies, found in southern Ohio

A male double-ringed pennant/Jim McCormac

Nature: Double-ringed pennants, other dragonflies, found in southern Ohio

Columbus Dispatch
August 1, 2021

NATURE
Jim McCormac

Jim Lemon spent his career in information technology at Ohio State University, but he’s an entomologist at heart. And by training. Following his retirement a few years ago, he launched back into the bug world with a passion. Dragonflies became his primary target, and Lemon is now one of Ohio’s leading odonatologists (a person who studies insects).

Back on June 29, Lemon and I headed afield to hunt dragons. Our destination was the wilds of Jackson and Pike counties. Our targets: two of Ohio’s rarest dragonflies.

The day dawned hot, sunny, and steamy, ultimately reaching 93 degrees with what felt like 100% humidity. Not so fun for human dragon-slayers, but great for the insects. They thrive in such weather and are at their most active.

We arrived at a remote abandoned sand-mining operation dotted with small spring-fed wetlands and the dragons soon came in abundance. Large blueberry-colored slaty skimmers dashed about, chasing interlopers who dared enter their turf.

Larger yet were spangled skimmers, a far more uncommon species. Males are powdery-blue with clear wings tipped with prominent white marks called stigmas. These create a blurred kaleidoscope effect in flight. A huge bonus was a stunning golden-winged skimmer. This big dragonfly is infused throughout with rich tones of gold, as if lit by the setting sun. A southerner, it is a vagrant to the upper Midwest and has only been found in six Ohio counties.

It didn’t take long to find our target, the yellow-sided skimmer. This species is sexually dimorphic: males look nothing like females. The former is showy blue, with the thorax sides washed in pale yellow. Females are brown with prominent yellow stripes running the length of the body.

The yellow-sided skimmer is a southern species and this locale harbors the only known extant Ohio population. Until recently, there was another site a few miles away but that population seems to have vanished. Fortunately, naturalist Nina Harfmann located this new site earlier this year.

Lemon and I saw about 20 individuals, the males ferociously guarding territories. This colony is one of the northernmost and is 100 miles or more from the nearest population in West Virginia.

Denison University entomologist Tom Schultz discovered the original Ohio yellow-sided skimmer site in 1998. I suspect this species had long been present but overlooked. They favor sunny densely vegetated openings fed by seeps. Such sites are not common, often tiny, and easily missed or ignored.

Soon we were off to a small pond south of Jackson. The little water body reminded me of countless farm ponds that I’ve seen, but this one was dragon magic.

Many calico pennants perched atop waterside plants, hawking insects and badgering one another. The male is gorgeous scarlet-red. Better yet were numerous banded pennants, a much less common and widespread dragonfly in Ohio. At rest on hot days, pennants frequently “obelisk”: raise their abdomens toward the sun, to minimize heat absorption.

But we had come to see Ohio’s only population of double-ringed pennants. A few dozen were present. They are not shrinking violets and we saw them instantly upon arrival. While lacking the visual pizazz of the other pennants, the double-ringeds are architecturally ornate, behaviorally interesting, and ooze charisma. The male in the photo shown here is in the obelisk position.

These double-ringed pennants were discovered in 2019, the first documented Ohio record. This year, another was photographed near Cincinnati. This is a southern and Atlantic coastal plain species with few Midwest records. I suspect it is a recent colonizer.

There is no doubt that some southern dragonfly species are rapidly expanding northward. It will be interesting to see what turns up in future years.

Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at www.jimmccormac.blogspot.com.

 

3 comments:

Dr. Bernard Master said...

Hey Jim.
Check your definition of odonatologist.
Vireo

Jim McCormac said...

Odonatologist: https://www.google.com/amp/s/www.collinsdictionary.com/us/amp/english/odonatologist

Jim McCormac said...

Odonatologist: “ a person who studies or is expert in insects that belong to the zoological group Odonata”