Ebony Jewelwings (Calopteryx maculata) in the wheel, Schulenberg Prairie, The Morton Arboretum, Lisle, Ilinois. (6-9-2017) Copyright Cindy Crosby.
DSA Species of the Month for December
Ebony Jewelwing (Calopteryx maculata)
DSA’s December “Species of the Month” is the Ebony Jewelwing (Calopteryx maculata) in the family Calopterygidae, the broad-winged damselflies, sometimes called jewelwings. Dennis Paulson, in Dragonflies and Damselflies of North America, tells us the Ebony Jewelwing is unique in that “no other North American damselfly is metallic green with black wings.” Its large size alone (39-57 mm or 1.5-2.25 inches) is distinctive, he says. The Ebony Jewelwing is found through most of the eastern half of the United States, into Canada, along wooded streams and sometimes away from streams. Find out how this species ignited a passion for dragonflies for writer Cindy Crosby in our final DSA blog post for 2024.
A Sense of Wonder
It began with Ebony Jewelwings.
After a difficult move decades ago, I spent almost every evening walking at an arboretum a few miles down the road from our new home in the Chicago region. I would stop on a bridge over Willoway Brook which ran through a tallgrass prairie, sit, and write in my journal. As I wrote, the life of the prairie unfolded around me and my difficulties didn’t seem as arduous. Muskrats swam down the waterway, carrying leafy vegetation to some unknown destination. Occasionally a coyote observed me from the clumps of big bluestem and switchgrass, then silently disappeared. Nature is always a great solace.
Bridge over Willoway Brook, Schulenberg Prairie, The Morton Arboretum, Lisle, Illinois. (9-6-20) Copyright Cindy Crosby.
And then, there were the damselflies.
At first as I watched the stream, I thought they were butterflies. Jet-black butterflies. Granted, that’s not too observant and no credit to myself, but at the time I was more concerned with writing in my journal than with insect identification. After a closer look, it was easy to see I was wrong. These were some other kind of insect. At the time, I knew pretty much zip about Odonata, so it took some sleuthing to discover they were damselflies. Ebony Jewelwing—Calopteryx maculata—damselflies to be precise.
Ebony Jewelwing (Calopteryx maculata), Nachusa Grasslands, Franklin Grove, Illinois. (6-30-22) Copyright Cindy Crosby.
Paulson, in his superb guide Dragonflies and Damselflies of the East, tells us that “no other North American damselfly is metallic green with black wings.” Watching these dusky damselflies flutter across Willoway Brook before sunset was a spark that ignited a two decades long passion in me for all things Odonata. Today, I know that Ebony Jewelwings are numerous and common in Illinois. But at the time—to someone who knew little about the insect world— they seemed rare. Unique. Because they were new to me. And they were something I’d never paid attention to before.
Ebony Jewelwing (Calopteryx maculata) and American Rubyspot (Hetaerina americana), Schulenberg Prairie, The Morton Arboretum, Lisle, Illinois. (6-13-21) Copyright Cindy Crosby.
As a dragonfly monitor years later (yes! I caught the “bug”), I turned through the pages of my field guides, trying to go beyond a simple identification to understand more about their life cycle and habits. Ed Lam writes in his excellent guide Damselflies of the Northeast that this species prefers “shaded forest streams” but is found at a variety of running waters (which includes my prairie waterways). Paulson notes their “night roosts may be communal, deep in tall grass” noting that they also roost in trees. I’ve still never seen them settling in after sundown. Think of all those jet-black wings fluttering in the dark!
Their iridescent emerald bodies change color in the sun—sometimes green, sometimes sapphire, sometimes a bit gold, sometimes almost ashy. The females have a white pseudostigma on the wings, which looks like a dot of Wite-Out. Be cautioned: You have to be a member of the typewriter age to know what Wite-Out is — some of my younger students give me blank looks when I describe the damselfly this way.
Female Ebony Jewelwing (Calopteryx maculata), Schulenberg Prairie, The Morton Arboretum, Lisle, IL. (6-14-2017) Copyright Cindy Crosby.
Today, I still have trouble distinguishing the female Ebony Jewelwings from the female River Jewelwings at one of the streams I monitor where they overlap. Robert DuBois, in his stellar field guide Damselflies of Minnesota, Wisconsin, and Michigan, tells me the Ebony Jewelwing female’s wings are broader and darker than the River Jewelwing female’s, and the pseudostigma is wider.
Male Ebony Jewelwings (Calopteryx maculata) and male River Jewelwing (Calopteryx aequabilis), Nachusa Grasslands, Franklin Grove, IL (6-30-2022) Copyright Cindy Crosby.
But when I’m balancing my camera, net, and clipboard, trying to distinguish the difference while standing mid-stream in waders, I’m not always confident. Like all else with Odonata, I believe if I practice paying attention to them long enough, the differences will be easier to detect. Or at least, practice will make me more proficient than I am now.
Ebony Jewelwing (Calopteryx maculata), Schulenberg Prairie, The Morton Arboretum, Lisle, IL. (6-14-21) Copyright Cindy Crosby.
Females may oviposit into submerged logs or vegetation, but can also submerge underwater. The first time I read about this, I was stunned. Adult damselflies going under the water’s surface? I had no idea! I later learned from several sources that the River Jewelwing females may submerge to oviposit as well. What a wonder! The jewelwings live such short lives as adults—usually less than a month— it seems only honorable and just that we should admire them while they are aloft along the streams.
Ebony Jewelwings (Calpteryx maculata) in the wheel, Schulenberg Prairie, The Morton Arboretum, Lisle, IL. (6-9-2017) Copyright Cindy Crosby.
Now, more than two decades after sitting on that bridge, journaling—and as a natural history instructor and someone who works with Odonata as a citizen scientist— I’ve never lost my love for the Ebony Jewelwing. Are they common? Absolutely. But they are no less charming for that. I’ll always be captivated by the flash of black wings in motion on the edges of a stream. Ebony Jewelwings will always kindle a sense of wonder in me.
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Cindy Crosby is the author of Chasing Dragonflies: A Natural, Cultural, and Personal History (Northwestern University Press, 2020) as well as other books about the natural world. She helps coordinate the efforts of dragonfly monitors on two Illinois sites, and regularly teaches and speaks on the joys of Odonata. Dragonflies regularly make appearances in her weekly blog, Tuesdays in the Tallgrass (at Wordpress). Contact Cindy or find out more about her work at www.cindycrosby.com.
