Species of the Month

Treeline Emerald (Somatochlora sahlbergi) male on willow at pond along airstrip, Old Crow, Yukon, 67.573° N 139.825° W, 7 July 1983. Photo: Rob Cannings.

March Species of the Month:

Treeline Emerald (Somatochlora sahlbergi )

DSA’s March “Species of the Month” is the Treeline Emerald (Somatochlora sahlbergi) in the family Corduliidae, the Emerald dragonflies. The Treeline Emerald is 48–50 mm in length (approximately 2 inches) and ranges across northern Eurasia, eastwards into Alaska, the Yukon, and a bit of the Northwest Territories. Find out how this species became a favorite subject for Syd and Rob Cannings in the third DSA blog post for 2025.

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A Denizen of the Northern Taiga

Back in 1979, I (Syd) was a dragonfly newbie—I’d learned on the fly, as it were, helping my older brother Rob gather information for his Dragonflies of British Columbia handbook (1977). And I had just landed a fantastic job, spending a summer in the Yukon surveying insects as part of the Biological Survey of Canada’s Yukon project.

Before I headed north from Vancouver, odonata expert Dennis Paulson told me to watch out for Somatochlora sahlbergi—an almost mythical dragonfly (it seemed to me) at the time. This dragonfly of the far North was named after the Finnish entomologist, Johan Reinhold Sahlberg (1845–1920). I looked up the species in the third volume of Walker and Corbet’s The Odonata of Canada and Alaska, which had just appeared four years earlier, and they listed only three records for North America: “Kuskokwim River” and Sagwon in Alaska, and Reindeer Depot (now called Reindeer Station) near the mouth of the Mackenzie River in Canada’s Northwest Territories.

Treeline Emerald male (Somatochlora sahlbergi) perched on low vegetation, sheltering from the wind near Nuorgam, Utsjoki municipality, Finland, 24 July 2009. Photo: Sami Karjalainen. From A. Schröter, T. Schneider, E. Schneider, S. Karjalainen, and M. Hämäläinen. 2012. Observations on adult Somatochlora sahlbergi – a species at risk due to regional climate change? (Odonata: Corduliidae). Libellula 31: 41–60. Used with permission.

But although I looked for the species in 1979, I never saw any flying, even though I had briefly driven the just-opened Dempster Highway north past the Arctic Circle and back again. I blamed the foggy weather! I did, however, see an amazing landscape that drew me back again for the next two decades until I finally moved to the Yukon in 2003.

My twin brother Richard (Dick) was tasked with the Yukon insect surveys in 1980, and he focused on the Dempster Highway. Where the highway follows the Ogilvie River, about 65.4° N latitude, he discovered that Treeline Emeralds were common in the valley’s fen ponds and oxbows. We were starting to get to know this mystery beast! I found my first Treeline Emerald the next summer, this time along the Porcupine River in the far north of the Yukon.

Syd Cannings waiting for patrolling Treeline Emeralds (Somatochlora sahlbergi) along the Ogilvie River at km 207, Dempster Highway, Yukon, 65.427° N 138.227° W, 21 July 2009. Photo: Rob Cannings.

The Treeline Emerald is a denizen of the northern taiga—the immense boreal forests stretching across Eurasia and North America. In fact, its southern distributional limit lies farther north than that of any other odonate. In Europe it doesn’t stray south of the Arctic Circle and in northwestern North America most of its populations are north of about 64º N, generally not far from the latitudinal treeline—giving the species its common name. Only in the mountains of eastern and southern Siberia, where it probably lives in isolated populations, does it range south to 51º N. Because the Treeline Emerald lives in remote places, mostly far from roads, dragonfly enthusiasts must undertake a real expedition to find it. Its distribution also seems to be patchy—over its vast range it still is known from fewer than 80 localities.

The range of the Treeline Emerald closely matches the distribution of widespread permafrost—permanently frozen ground. In the northern Yukon and central Alaska, it inhabits peatland ponds underlain by permafrost and topped with floating fen mosses. As you wade out from the pond edge to get close to the patrolling males or ovipositing females, your boots slide on solid ice beneath the peaty muck. In many ponds the slippery ice slopes down to the deep center. You don’t want to fall in! In northern Scandinavia the hummocky tundra habitat of the dragonfly is called “palsa mires”.

Treeline Emerald (Somatochlora sahlbergi) habitat: fen in permafrost along the Blackstone River, Yukon, 65.064º N 138.128º W, 29 June 2019. Photo: Cameron Eckert. Used with permission.

I returned to the Dempster Highway in 1982 and collected several Treeline Emeralds, including many larvae. The larvae clustered into several size-groups, indicating a lifespan of about five, or maybe even six, years—rather long for a modest-sized dragonfly. Larvae were emerging around July 1, and because autumn frosts at that latitude begin in the last two weeks of August, the dragonflies really only can grow during about six weeks each year. Once I knew how to identify the larvae, I discovered that I had found one on my first trip north in 1979! We redescribed the larva based on our collections and documented habitat and other biological information.

Rob Cannings’ illustration of a Treeline Emerald (Somatochlora sahlbergi) larva, from Cannings, S.G. and R.A. Cannings. 1985. The larva of Somatochlora sahlbergi Trybom (Odonata: Corduliidae) with notes on the species in the Yukon Territory, Canada. Odonatologica 14: 3l9–330.

Recent genetic work by Manpreet Kohli and her colleagues shows that the Treeline Emerald has remarkably limited genetic diversity over its immense range on both sides of the Bering Strait. There are several possible explanations for this, but perhaps the most likely one is that colonization of North America occurred relatively recently (less than 10,000 years ago) by a small number of individuals. The relatively long (for a dragonfly) life cycle of the Treeline Emerald would have also limited its post-glacial diversification.

Where its range overlaps with those of the Ringed Emerald (Somatochlora albicincta) and the Hudsonian Emerald (S. hudsonica), considerable hybridization occurs. Hybrids have been found in central Alaska, the Mackenzie River Valley, and the northern Yukon. In these places, obvious hybrids make up about 20 percent of all Emeralds recorded. Hybrids have color patterns and structural characteristics intermediate between those of the parent species.

Rob Cannings hunting Treeline Emeralds (Somatochlora sahlbergi) along the Ogilvie River at km 207, Dempster Highway, Yukon, 65.427º N 138.227º W, 21 July 2009. Photo: Syd Cannings.

Obvious hybrids are not often encountered in dragonfly-watching, and this is the result of “good” female choice. Male dragonflies are not very selective when seeking mates; they will try to mate with any female that is about the right size and shape! It’s the female that decides whether or not to mate. So, apparently, a hybrid results when a female mistakenly accepts a male from a different species. The presence of hybridization in this case tells us that the Treeline Emerald is probably a recent immigrant to North America and is still “learning” to distinguish its new neighbors.

Normally, the three species of emeralds separate themselves by larval habitat: the Treeline Emerald develops in permafrost ponds with floating moss, the Ringed Emerald prefers shallow ponds with little vegetation, and the Hudsonian Emerald lives in ponds with tall sedge edges. But sometimes, wetlands occur that combine two or more of these habitats in close proximity, and in these places the three species may encounter one another.

Treeline Emerald (Somatochlora sahlbergi) habitat; hybrids with Hudsonian Emerald (S. hudsonica) have also been found at this site. Polygon fen in tundra in the Porcupine River drainage, 20 km SW of Old Crow, Yukon, 67.417º N 140.083º W, 5 July1983. Photo: Rob Cannings.

Finally, even though this species can be abundant in its favored habitats, its requirements (permafrost in a dry climate) put the Treeline Emerald at great risk in the face of rapid climate change. The North is warming quickly, much more quickly than temperate areas, and this means that permafrost is disappearing. In parts of the North, the climate is becoming wetter as well, a change which will also reduce the amount of permafrost. I revisited some of my 1982 sites in 2009 and 2019, and evidently the peatlands had dried considerably, presumably because the underlying permafrost had melted. At one site where Treeline Emeralds were once abundant, I could only find the widespread Ringed Emerald. 

More thorough monitoring is needed both here and in Eurasia . . . if anyone would like to join in, let us know!

Acknowledgements

 We thank Sami Karjalainen and Cameron Eckert for permission to include their photographs.

Our guest bloggers are Syd and Rob Cannings, who grew up beside a grassland in British Columbia’s Okanagan Valley in a family known across Canada for its contributions to natural history and conservation. Both are founding members of the DSA. 

Syd has recently retired as a Species at Risk Biologist for the Canadian Wildlife Service in Whitehorse, Yukon. He is an author of several books, including British Columbia: A Natural History and The New B.C. Roadside Naturalist. Email him at syd.cannings@gmail.com.

Rob is an Emeritus Curator at the Royal BC Museum in Victoria, BC, where he was Curator of Entomology from 1980 to 2013. He mainly studies the systematics and faunistics of Odonata and Asilidae (Diptera) but publishes on a variety of insect orders. He is the author of several books, including Introducing the Dragonflies of British Columbia and the Yukon. He can be reached at rcannings@royalbcmuseum.bc.ca.

Species of the Month

Sabino Dancer (Argia sabino) September 16, 2018, Sycamore Canyon, Santa Cruz County, Arizona. Copyright Pierre Deviche.

February Species of the Month: Sabino Dancer Damselfly (Argia sabino)

 DSA’s February “Species of the Month” is the Sabino Dancer damselfly (Argia sabino) in the family Coenagrionidae. It is 35-40 mm in length (about 1 ½ inches) and can be found in canyons with rocky plunge pools. Its range is limited to south in the Mexican uplands to Jalisco, Mexico, and into southern Arizona, according to Dennis Paulson in Dragonflies and Damselflies of the West. Join Arizona State University Emeritus Professor Pierre Deviche as he discusses this exciting species and some of its damselfly relatives.

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Arizona Blues: Sabino Dancer and Some Look-Alike Congeners

Odonate species richness in the United States varies greatly from one region to another and is generally highest in the eastern half of the country (Abbott et al., 2022). From this standpoint, Arizona does not fare particularly well. One hundred and forty-nine species have been recorded in the state (Odonata Central). To compare, 197, 188, and 186 species have been documented in Virginia, New Jersey, and Pennsylvania, respectively, despite Arizona being at least 60% larger than any of these states. Even within western states, Arizona does not shine with regard to its odonate richness (e.g., Texas: 251 species; New Mexico: 151 species; Table 1).

Table 1: Number of dancer (Argia) species and of odonate species recorded in the U.S., in selected western U.S. states, and in Sonora, Mexico. For each region, the table shows the ratio between the number of Argia species and the total number of odonate species. Data from Odonata Central, January 2025.

But! When it comes to comparing species richness at a finer scale,  a remarkable exception to the above is provided by the dancers (Argia): 28 species, i.e., 78% of the species (36) found in the U.S., have been documented in Arizona. Perhaps more impressive, dancers represent 19% of the Arizona odonate species (Table 1). By comparison, this percentage for other western states is “only” 13% (New Mexico) and 9% (Texas). Even the state of Sonora (Mexico), which borders Arizona and has a great diversity of biotopes with northern and southern affinities including subtropical forests, has “only” 24 Argia species, although they comprise 23% of the number of odonate taxa found in this state (Table 1).

A number of Arizona locations have 13 Argia species or more, including: Muleshoe Ranch (Cochise County), Queen Valley (Pinal County), Sonoita Creek (Santa Cruz County), Bonita Creek (Graham County), and Lower Eagle Creek (Greenlee County). 

Another eye-catching feature of the Arizona damselfly fauna is that nine Argia species have not been recorded elsewhere in the country. Two species are accidental (Yaqui Dancer, A. carlcooki [single record: Bailowitz et al., 2015] and Oculate Dancer, A. oculata [single record: Odonata Central record OC#473018]) but the others can be found regularly or more or less so in appropriate habitats: Cerulean Dancer, A. anceps, Harkness’s Dancer, A. harknessi, Sierra Madre Dancer, A. lacrimans, Pima Dancer, A. pima, Sabino Dancer, A. sabino, Tarascan Dancer, A. tarascana, and the recently described Marsh Dancer, A. paludicola (Garrison and Von Ellenrieder, 2022; Deviche and Garrison, 2022).

 Several Arizona Argia species are widely distributed and occupy diverse habitats with running water. Such is, for instance, the case of the Lavender Dancer, A. hinei, Sooty Dancer, A. lugens, Aztec Dancer, A. nahuana, and Springwater Dancer, A. funebris. To our knowledge, however, four species (Marsh, Sabino, Pima, and Tarascan Dancers) have established populations only at a handful of discrete and in three cases, widely separated sites (Figure 1).

United States known distribution of four dancer (Argia) species as per Odonata Central, January 2025. Note: As per Bailowitz et al. (2015) the Sabino Dancer, Argia sabino, has been found also in the Galiuro Mountains (between Tucson and Safford) and the Santa Rita Mountains (south of Tucson), and the Pima Dancer, Argia pima, has been documented also in the Santa Catalina Mountains (just northeast of Tucson). Copyright Pierre Deviche.

The Marsh Dancer is morphologically distinct and contrary to the other species, it occupies high elevation (> 2,200 m) marshy habitats (Garrison and Von Ellenrieder, 2022; http://azdragonfly.org/species/marsh-dancer). Its field identification based on visual cues and habitat is, therefore, straightforward. The Sabino Dancer, along with the Pima Dancer, was not described until 1994 (Garrison, 1994). These two species are thought to be taxonomically closely related to each other but less so to the Tarascan Dancer (Caesar and Wenzel, 2009). The three dancers subtly differ with regard to the shape and width of humeral stripes as well as coloration of abdominal segments (Figures 2 and 3). As they also show considerable regional and/or individual variation (Burns, 2015; http://azdragonfly.org/news/individual-variation-humeral-stripe-tarascan-dancer-argia-tarascana), 

it would seem that identifying them—especially females— in the field must present a major challenge. This is, however, not entirely the case. Indeed, the locations of their colonies do for the most part not overlap, i.e., most sites hold only one of the three species (Figure 1). In addition, each species appears to preferentially occupy a distinct habitat. Sabino Dancers are usually found at rocky perennial streams with cataracts and plunge pools (Paulson, 2009; Bailowitz et al., 2015). In contrast, Tarascan Dancers are partial to shallow pools of streams and rivers with overhanging vegetation, and Pima Dancers fancy rocky streams in forested areas (Paulson, 2009; Figure 4).

Male Sabino Dancer (Argia sabino) September 16, 2018, Sycamore Canyon, Santa Cruz County, Arizona; Tarascan Dancer (Argia tarascana), August 28, 2022,  Muleshoe Ranch, Cochise County, Arizona; and Pima Dancer (Argia pima), August 6, 2018, Sonora, Mexico. Copyright Pierre Deviche.

Female Sabino Dancer (Argia sabino) September 9, 2017,  Sycamore Canyon, Santa Cruz County, Arizona;, Tarascan Dancer (Argia tarascana), September 7, 2013, Muleshoe Ranch, Cochise County, Arizona; and Pima Dancer (Argia pima), August 10, 2020, Wet Beaver Creek, Yavapai County, Arizona. Copyright Pierre Deviche.

Typical Arizona habitat of (A) the Tarascan Dancer, Argia tarascana (May 29, 2016; Muleshoe Ranch, Cochise County, Arizona) and (B) the Pima Dancer, Argia pima (July 7, 2018; Wet Beaver Creek, Yavapai County, Arizona). Copyright Pierre Deviche.

The Sabino Dancer and its close congeners, the Pima and Tarascan Dancers, deserve special attention for another reason. It is already known that the Sabino Dancer’s local abundance fluctuates annually and presumably as a function of local changes in precipitation (Westfall and May, 2006). In the past 20 years the American Southwest has witnessed intense drought, resulting in landscape aridification and considerable stress on the water resources of this already dry region (Wahl et al., 2022). These authors consider it unlikely that recovery of the current moisture deficit will take place in the next decades. Compounding this effect, the region is experiencing climate warming and increased use of water resources associated with agriculture and rapid urbanization. Odonates depend on aquatic environments and the consequences of long-term drought conditions, climate warming, and human encroachment on their populations generally remain understudied. 

The Sabino, Pima, and Tarascan Dancers occupy limited habitats and presumably have low ability for dispersal. These taxa may, therefore, be particularly sensitive to changes in environmental conditions, and their distributions and abundance warrant close regular monitoring. Could persistent region-wide drought in the coming decades lead to severe range shrinkage and, perish the thought, even extirpation of these species from the U.S. odonate fauna? Time will tell….

 Fortunately, we are not there yet. A particularly enticing location to see Argia species  is Sycamore Canyon (Santa Cruz Co.), which is in the heart of the Pajarito Mountains and extends into northern Sonora (Figure 5). The canyon has long been cherished by birders who visit it hoping to find rare species such as the Elegant Trogon, Rufous-capped Warbler, and Five-striped Sparrow. Odonates are well represented: 54 species have been documented including Mayan Setwing, Dythemis maya, Straight-tipped Ringtail, Erpetogomphus elaps, and White-tailed Sylph, Macrothemis pseudimitans (http://azdragonfly.org/locations/sycamore-canyon-santa-cruz).

Sycamore Canyon also stands out in other respects. It is one of the U.S. sites with the highest known richness in Argia. Fifteen species (i.e., > 40% of the U.S. taxa) have been recorded to date, among which the Oculate Dancer (only U.S. record) and the Cerulean Dancer (first U.S. record; Danforth et al., 2013), a species whose range has greatly expanded in the southern half of Arizona during the past 10 years. Sycamore Canyon also is one of the few U.S. locations holding a population of Sabino Dancers (Figure 1). 

Next time you travel to Arizona during the summer, plan on visiting Sycamore Canyon and discover its rich odonate diversity. With luck on your side, you may chance upon some Sabino Dancers.

(A). View of the Pajarito Mountains and (B) Sycamore Canyon, Santa Cruz County, Arizona. Both photos September 23, 2007. Copyright Pierre Deviche.

Pierre Deviche is Professor Emeritus at Arizona State University in Tempe, Arizona, where he investigated physiological and behavioral adaptations of vertebrates to their natural environments and to urbanization. Contact him at deviche@asu.edu.

References

Abbott JC, Bota-Sierra CA, Guralnick R, Kalkman V, González-Soriano E, Novelo-Gutiérrez R, Bybee S, Ware J, Belitz MW. 2022. Diversity of Nearctic Dragonflies and Damselflies. Diversity 14, 575. https://doi.org/10.3390/d14070575.

 Bailowitz, R, Danforth, D, Upson, S. 2015. A Field Guide to the Damselflies and Dragonflies of Arizona and Sonora. Nova Granada Guides, Tucson, Arizona, 459 pp.

 Burns J. 2015. Variation in Cerulean Dancer (Argia anceps) in Costa Rica and Arizona. ARGIA 27: 17.

Caesar RM, Wenzel JW. 2009. A Phylogenetic Test of Classical Species Groups in Argia (Odonata: Coenagrionidae). Entomol. Americ. 115, 97-108.

 Danforth D, Bailowitz R, Deviche P. 2013. Cerulean Dancer, Argia anceps, a new species for the United States. ARGIA 25: 10-11.

 Deviche P, Garrison RW. 2022. Hidden in plain view: The discovery of the Arizona Marsh Dancer, Argia paludicola Garrison and von Ellenrieder. ARGIA 34: 30-35.

 Garrison RW. 1994. A Synopsis of the Genus Argia of the United States with Keys and Descriptions of New Species, Argia sabino, A. leonorae, and A. pima (Odonata: Coenagrionidae). Trans. Amer. Entomol. Soc. 120: 287-368.

 Garrison RW, Von Ellenrieder N. 2022. Damselflies of the genus Argia Rambur, 1842 (Odonata: Coenagrionidae) from Mexico, Central America and the Lesser Antilles with descriptions of five new species. Zootaxa 5201: 001–439.

 Odonata Central: https://www.odonatacentral.org/#/

 Paulson, D. 2009. Dragonflies and Damselflies of the West. Princeton Univ. Press, Princeton, NJ, 535 pp.

 Wahl ER, Zorita E., Diaz HF, Hoel A. 2022. Southwestern United States drought of the 21st century presages drier conditions into the future. Comm. Earth Environ. 3: 202.

 Westfall MJ, May ML. 2006. Damselflies of North America. Scientific Publishers, Gainesville, FL, 502 pp.

Species of the Month

Widow Skimmer (Libellula luctuosa) female, Silver Falls Rest Area, Texas, USA (6-22-2021) Copyright Danielle Husband.

DSA Species of the Month for January: Widow Skimmer (Libellula luctuosa)

DSA’s January “Species of the Month” is the Widow Skimmer (Libellula luctuosa) in the family Libellulidae, the king skimmer dragonflies. The Widow Skimmer is 42–50 mm in length (approximately 1.7–2 inches) and is found across most of North America except the Rocky Mountain region in the United States, through Mexico, and in four Canadian provinces. Find out how this species became a favorite subject for biologist and DSA webmaster Danielle Husband in our first DSA blog post for 2025.

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“I’m Ready For My Closeup, Ms. Husband!”

My world changed when I received my first digital camera as a tween. As a budding naturalist, I took to the great outdoors. To me, North Florida nature was the best. There were always lizards, birds, flowers, alligators, and more to see. Even right in my backyard! I documented “life in the backyard“ just like I saw photographers and videographers do on a bigger scale in National Geographic or on Animal Planet.

Fast forward two decades and I am a camera owner again (shout out to the DSA Odonate Research Grant Program). During my master’s degree research, I amassed a library of odonate images at different wetland sites in the Texas Panhandle. These voucher photos served as visual evidence of species presence at a site. However, taking a clear image of each species observed was a real challenge. The life of an adult dragonfly is a quick one; it makes sense that they’d be on the move. Many individuals make you work for the photo. If I was fortunate, I snapped a few pictures either by frantically running around or crouching low before the individual made a quick exit. Some days you need a win. Luckily one special dragonfly was ready for its closeup. The Widow Skimmer.

Widow Skimmer (Libellula luctuosa) male, Tahoka Lake, Texas, USA (6-12-2021) Copyright Danielle Husband.

The Widow Skimmer earned the “widow” name for its dark brown wing bands on either side of the thorax, which are said to resemble a draped mourning cloth. Males have a showy white band near the center of their wings and abdomens that become more “pruinose” or whitish with age. Females lack the white wing band and feature yellow stripes on each side of their abdomens.

Widow Skimmer (Libellula luctuosa) female, Silver Falls Rest Area, Texas, USA (6-22-2021) Copyright Danielle Husband.

Widow Skimmers perched when other dragonflies I observed rarely did. I’d find them resting on reeds or blades of grass. They were quick to rise above the vegetation, catch an insect or chase off another dragonfly, and then land again.

Widow Skimmer (Libellula luctuosa) male in flight, Elm Park, Lubbock, Texas, USA (6-19-2021) Copyright Danielle Husband.

It was hard not to ignore them at each site. On a sunny summer day, males appear to glow in the summer sun. The female’s abdominal stripes stood out with golden flair.

Two Widow Skimmer (Libellula luctuosa) males, Silver Falls Rest Area, Crosby County, Texas, USA (6-22-2021) Copyright Danielle Husband.

A common perching odonate is the perfect beginner photographer’s subject. Take note of what odonate is saying, “I’m ready for my closeup” around you. Who knows? The Widow Skimmer might be exactly what you need to kick off your odonate photography journey. 

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Danielle Husband is responsible for the care and feeding of the DSA website. She works as a wildlife biologist in Washington State and is a Texas Tech McIntyre Lab alumna. Contact her at webmaster@dragonflysocietyamericas.org with questions or DSA website recommendations. 

*Measurements are from Dragonflies and Damselflies of the East by Dennis Paulson, Princeton University Press (2011)

Species of the Month

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.

****

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.

Species of the Month

Common Green Darner (Anax junius), Black River State Park, Jackson County, Wisconsin. (2017) Copyright Ken Tennessen.

November Species of the Month: Common Green Darner (Anax junius)

DSA’s November “Species of the Month” is the Common Green Darner (Anax junius) in the family Aeshnidae. It is a migratory species, 68-78 mm in length (about two and a half to three inches), and is found throughout most of the United States north into Canada and south into Mexico and Central America, as well as many other parts of the world. Its preferred habitat is lakes, ponds, or small streams but the Common Green Darner can be seen almost anywhere. Join Ode expert Ken Tennessen as he recounts an unusual experience with this migratory species.

Ode To An Unusual Feast

A frenzy of Anax junius (Common Green Darners) bedazzled my hometown of Wautoma in Waushara County, Wisconsin. They appeared along east Mt. Morris Street (lat/long 44.0757, -89.2873)) in the late afternoon of September 20, 2024. I first noticed them a little after 6 p.m., but there were already lots of them, so the activity had started before that. 

Common Green Darner (Anax junius), Sandhill Wildlife Management Area, Wood County, Wisconsin. (2006) Copyright Ken Tennessen.

With no way to count them, I estimated that hundreds were zipping about, flying fast and low, for several blocks as far as I could see. Temperature was 78 degrees Fahrenheit and relative humidity was 53 percent.

Common Green Darner (Anax junius), The Morton Arboretum, Lisle, Illinois. (9-5-20) Copyright Cindy Crosby

Silhouetted against the sun, I could see a variety of small insects flying above the lawns, but I think the Common Green Darners were concentrating on the winged ants that must have been dispersing from some gallery in the neighborhood. I soon deduced that the dragonflies must be eating just the abdomens of the ants, as I found dozens of partial bodies on the sidewalk. Only the head, thorax, and wings remained. The mutilated ants were still alive and crawling frantically but with the abdomen missing (Fig. 1) they could no longer fly.

Remains of citronella ants (Lasius sp.) found crawling on the sidewalk without their abdomens, after being attacked by Anax junius; Wautoma, Wisconsin. (9-20-24) Copyright Ken Tennessen.

P.J. Liesch of the Insect Diagnostic Lab at the University of Wisconsin confirmed the prey to be citronella ants in the genus Lasius. I found one report of adult Anax junius feeding on ants, by Warren (1915), who studied this species feeding in Hawaii; however, he did not identify any specific type of ant. My observations may constitute the first specific report of dragonflies feeding on citronella ants. Lasius belongs to the subfamily Formicinae (Boudinot et al. 2022), so apparently they produce formic acid. How much acid these ants produce is questionable, but it appears it did not deter the dragonflies from ingesting them. Formic acid is produced in the gaster (abdomen). So, that is what the “CGDs” were eating!

Common Green Darner (Anax junius), The Morton Arboretum, Lisle, Illinois. (7-9-21) Copyright Cindy Crosby.

Easy to recognize, the Common Green Darner has a distinctive black "bulls eye" mark on its head, in front of the huge eyes. Males have a green thorax but are largely blue on the abdomen, whereas females are green and rusty brown. The female often oviposits in tandem with the male but also lays eggs alone.

Common Green Darners (Anax junius), Nachusa Grasslands, Franklin Grove, Illinois. (6-9-24) Copyright Cindy Crosby.

This species is known to migrate long distances, feeding voraciously on other insects, storing fat and protein. They show up in Wisconsin in early spring when it is still quite cold and before the resident population emerges. Our spring migrants come from points far south; in the fall, the next generation heads south. Much has yet to be learned about their migratory routes and life history traits.

Around 6:30 p.m., with the sun near the horizon, the number of Common Green Darners decreased abruptly, and shortly afterwards I saw only a few individuals. They left me with questions. Where did  they go? Will they show up again tomorrow? If not, where are they going? How did they form the swarm and find the winged ants? 

The only answer I can offer is, no, they did not show up the next day.

References

• Boudinot, B. E., M. L. Borowiec, and M. M. Prebus. 2022. Phylogeny, evolution, and classification of the ant genus Lasius, the tribe Lasiini and the subfamily Formicinae (Hymenoptera: Formididae). Systematic Entomology 47: 113–151.

• Warren, A. 1915. A study of the food habits of the Hawaiian dragonflies. Bulletin, College Hawaii Publications 3: 4–45.

• May, M. L., J. H. Matthews. 2008. Migration in Odonata: A case study of Anax junius. Pp 63–77 in Cordoba-Aguilar, A., (ed.) Dragonflies, model organisms for ecological and evolutionary research. Oxford University Press, Oxford.

More Migration Information

• May, M. 2013. A critical overview of progress in studies of migration of dragonflies (Odonata: Anisoptera), with emphasis on North America. Journal of Insect Conservation 17:1–15.

• C. Scott Clem and Joseph V. McHugh "Documentation of Diurnal and Nocturnal Migratory Activity of the Dragonfly Anax junius (Odonata: Aeshnidae) on Sapelo Island, Georgia, USA," Southeastern Naturalist 23(3), N54-N57, (7 October 2024). https://doi.org/10.1656/058.023.0316

• Russell, R. W., M. L. May, K. L. Soltesz, J. W. Fitzpatrick. 1998. Massive swarm migrations of dragonflies (Odonata) in Eastern North America. American Midland Naturalist 140:325–342.

*****

Ken Tennessen has studied dragonflies for over 50 years, publishing papers and books on their systematics, phylogeny, life cycle, behavior and conservation. A major work, Dragonfly Nymphs of North America, was published by Springer Nature in 2019. He has written numerous articles for DSA newsletters and has published over 80 technical papers in technical journals, including naming 22 new species of Odonata; four New World species are named for him. Email: tenkenneth43@gmail.com

*****

Editor’s note: This essay appeared in slightly different form first in Wisconsin Dragonfly Society’s Ode Notes September 2024. Introductory information is from Dennis Paulson’s Dragonflies and Damselflies of the East and Dragonflies and Damselflies of the West and other sources.

Species of the Month

October DSA Species of the Month: Striped Meadowhawk (Sympetrum pallipes)

Striped Meadowhawk (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

DSA Species of the Month for October 2024

October’s DSA species focus is the Striped Meadowhawk (Sympetrum pallipes), a common and widespread species in western North America. Averaging 36 mm (1.4 inches) in length, males are red and females brown or red like most meadowhawk species, but both sexes can be recognized by their prominent pale thoracic stripes. Follow odonate expert Dennis Paulson as he recounts his surprising encounter this autumn with these fascinating dragonflies.

Look and Ye Shall Find

Sometimes, you are fortunate when looking for odonates. This was the case in September, when my wife, Netta Smith, and I found these Striped Meadowhawks (Sympetrum pallipes).

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

The species name pallipes (pale-footed) is appropriate over much of the range, but not the wet Pacific Northwest, where the legs are black. Emerging in June and July, they fly as late as November in many areas. But they are locally distributed because of their habitat needs.

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

They are among the relatively few species of Odonata that breed in seasonal wetlands--they lay their eggs on land!

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

They breed in fall, when shallow ponds have dried up, and while in flight drop their eggs one by one into the herbaceous vegetation filling the dry basin. You can see their tiny white eggs being dropped in some of the following photos.

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

The eggs are dormant until spring, well after the pond has filled during winter rains. They then hatch and the nymphs grow rapidly to full size. The adults emerge from the water in early summer.  As soon as they mature sexually, they return to the now dry ponds and mate and oviposit.

 Just by luck on September 6, 2024, we found one of these dried-up but heavily vegetated pond basins at the edge of Cranberry Beach Road in Grayland, Washington. As one drives out this road, heavy low forest gives way to sand plains covered with herbaceous vegetation well back from the ocean beach. Parallel to the beach, there are depressions deep enough to hold water for part of the year. And there were the meadowhawks! I took more than 200 photos in 10 minutes at midday.

 The last photo (below) shows a female that might have been resting after a session of vigorous oviposition.

Striped Meadowhawks (Sympetrum pallipes), Cranberry Beach Road, Grayland, Washington; 9-6-24 (Photo copyright Dennis Paulson)

Sometimes, when looking for dragonflies, you find something wonderful! This was definitely one of those days.

***

Dennis Paulson is a biologist and a naturalist who grew up in Miami, exposed to subtropical nature in all its glory while southern Florida was still largely unspoiled. He received his Ph.D. in Zoology from the University of Miami in 1966 with a study of the dragonflies of southern Florida, and shortly thereafter he moved to Seattle, where he has lived ever since. He recently retired after 15 years of being the Director of the Slater Museum of Natural History at the University of Puget Sound, where he also taught in the Biology Department. He has also led nature tours and traveled to all continents.

Paulson has published over 75 scientific papers on his favorite animals, and his contributions to natural history include these books: Shorebirds of the Pacific Northwest; Shorebirds of North America: The Photographic Guide; Exotic Birds; Alaska: The Ecotraveller’s Wildlife Guide; Dragonflies and Damselflies of the West;, Dragonflies and Damselflies of the East; Dragonflies and Damselflies: A Natural History; ABA Field Guide to the Birds of Washington; and Dragonflies and Damselflies of Costa Rica.

Species of the Month

DSA Species of the Month for September: Philogenia martae

Philogenia martae (Male), Tatamá National Park, Colombia, 8-4-23. Copyright Dan Osipov.

DSA’s “Species of the Month” for September is the damselfly  Philogenia martae. It is in the Flatwing Family (Philogeniidae) and was newly described around 2017. Measuring about six centimeters (about 2.36 inches) long, this damselfly is endemic to the Western Colombian Andes mountain range in the Republic of Colombia in South America. Read on as photographer and dragonfly chaser Dan Osipov shares his experiences with this elusive species.

---

The Best “Bug Shot” of All

It had been abnormally dry in 2023, and the unassuming stream by the side of the road seemed like it could have been runoff from the rains. I was hiking the road cutting through the Tatamá National Park in Colombia in late July and August of 2023, the location of the 2022 Dragonfly Society of the America’s meeting. Now, the following year, I was there with a group of photographers for a “BugShot” tour. The forest was full of unique planthoppers, fancy beetles, and flamboyant butterflies. But my eyes were on dragonflies and damselflies.

Philogenia martae (Male), Tatamá National Park, Colombia, 8-4-23. Copyright Dan Osipov.jpg

There are more than one hundred unique species of odonates that reside in Tatamá National Park, making it a top biodiversity spot in the region. Some of the odonates there, including Philogenia martae, are endemic to the Western Cordillera region, and haven’t been found anywhere else on earth.

Philogenia martae (Male), Tatamá National Park, Colombia, 8-4-23. Copyright Dan Osipov.

The road I hiked ran from the park entrance to a military installation on top of the mountain. There were few other access points into the forest.  Each day, the dragonflies were most active when the sun shone from mid-morning until early afternoon. Once the clouds rolled in in the afternoon, they would settle high up in the trees or in deep vegetation. This made them much harder to spot.

It was near that unassuming stream that a pair of damselflies—Philogenia martae—were hanging out. I discovered a male P.martae on a branch early in the afternoon on my hike. I froze for a moment with surprise! 

Philogenia martae (Male), Tatamá National Park, Colombia, 8-4-23. Copyright Dan Osipov.jpg

At six centimeters (2.3 inches) in length, P. martae could rival some dragonfly darners in size, yet this damselfly’s slender constitution blended well with the surrounding vegetation. Once I found it, the damselfly posed for a few photos and videos. The next day I found a female sitting in the same spot, but she wasn’t as cooperative, flying up high as I approached.

Philogenia martae (Female), Tatamá National Park, Colombia, 8-5-23. Copyright Dan Osipov.

There are a number of other species of Philogenia (Flatwings) across Central and South America. The damselfly P. martae was described relatively recently in 2017, and is endemic to the Western Colombian Andes mountain range.  Its yellow face has been anthropomorphized as a smile.

Philogenia martae (Male), Tatamá National Park, Colombia, 8-4-23. (Enhanced) Copyright Dan Osipov.jpg

It has been a great privilege to observe this species in the wild.  And yes—-it made me smile to find it!

*****

Dan Osipov has been chasing dragonflies and damselflies since early childhood; first with a net, and more recently with a camera. He currently resides in the Bay Area of California. You can find him on Instagram or Threads. Danwould like to thank Juliana Sandoval, Kendra and John Abbott, Clay Bolt, Thomas Shahan, Cornelio Bota, as well as all the staff at the Montezuma Rainforest Ecolodge for making his experience with this damselfly possible.

Species of the Month

 August’s Featured Species: Laura’s Clubtail (Stylurus laurae)

Focus stacked image, Laura's Clubtail (Stylurus laurae) male, first sighting, 8-18-2023 Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

This month’s DSA species focus is Laura’s Clubtail (Stylurus laurae). Laura’s Clubtail is in the family Gomphidae, and is found from Northeastern Texas to the southernmost part of Ontario. It is between two and a quarter and two and three quarters inches long (54-64 cm), and in its northern range flies from July to August (longer in the south). Read on to hear about our August guest blogger Jay Heiser’s ongoing relationship with the species.

An Ohio Surprise

Late one afternoon on August 1, 2018, I was out walking on my property when I noticed something new perched on the side of the creek.  It was on some low vegetation just upstream from the township road bridge. With my longest camera lens, I could just barely get an identifiable photo of the strongly backlit dragonfly. Laura’s Clubtail (Stylurus laurae) !

Laura's Clubtail (Stylurus laurae), first sighting, 8-1-2018 Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

 I’d only been systematically observing Odonata for a couple of months and I wasn’t prepared for the minor excitement that ensued online when this turned out to be one of Ohio’s lesser seen species. I returned multiple times, and had sightings on the fourth and the 28th. The tattered wings and the consistency of location suggested that it may have been the same individual.

Although I didn’t find Laura's Clubtail in 2019, in the following four years, I was able to observe much of their adult life cycle. I saw and photographed a recently emerged teneral, flying up out of the creek bed and temporarily posing for a photo before leaving for a couple weeks.

Teneral Laura's Clubtail (Stylurus laurae) emerging from stream, 7-14-2021, Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

 I’ve witnessed males fighting over territory, and I’ve had females whiz around my Muck Boots as they deposited eggs.

Female Laura's Clubtail (Stylurus laurae) resting before resuming egg depositing Laura's Clubtail, 7-18-2020, Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

I only had single sightings in 2022 and 2023, but the latter posed for me at eye level in some beautiful golden sunlight.   

Perched males often buzz their wings, complicating photography, but this last subject stayed so perfectly still that I was able to record a series of focus bracketed photos that very neatly stacked into a single vivid and sharp image.

Male Laura's Clubtail (Stylurus laurae), vibrating its wings, 8-20-20, Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

Our property is located at the northeastern corner of the unglaciated Appalachian Plateau.Flowing through three miles of active and abandoned agricultural land before reaching us, the water course that defines our place’s northern border is much straighter and deeper than it was before European settlement. Along most of our property, including the places where I’ve found Laura’s Clubtail, the creek is about twice as wide as the embankment is high. It is sunny, with sparse tree cover.

Big Run Creek, 9-2-23, Killbuck, Ohio, USA (Photo copyright Jay G. Heiser).

 Starting at the downstream corner of our property, the shallower-banked creek is allowed to meander through shady woods for another mile before joining a tributary of the Muskingum River. The banks are mud, but the stream bed is composed of sand, eroded from the Pennsylvanian age sandstone that comprises our bedrock.   It is usually wadable in boots.Over the past five seasons, I’ve spent hours trudging up and down our 200 meters of creek bed, and have managed 19 Laura’s Clubtail sightings. 

While I’ve had occasional sightings of many Odonata species within or above the creek, it’s the Ebony Jewelwings (Calopteryx maculata), Variable Dancers (Argia fumipennis), Stream Bluets (Enallagma exsulans), and Ashy Clubtails (Phanogomphus lividus) that have regularly exhibited breeding activity within this habitat. The presence of species such as Least Brook Lampreys (Lampetra aepyptera) and Mudpuppy Salamanders (Necturus maculosus) suggests that in spite of agriculture, the water quality is relatively high.

Sightings peaked at seven in 2020 and have declined since then. It’s tempting to draw some conclusions about our local population, but with such a small set of observations, bias is likely. The species has historically been seen in six Ohio counties, most recently in two or three, and it is reasonable to expect that more breeding populations exist.

Confirmed Ohio Sightings of Laura's Clubtail (Stylurus laurae) January, 2024. Used with permission from the Ohio Odonata Society.

I believe that several factors could explain the relatively low rate of sightings. First, this is a species that spends very little of its adult life in places that are convenient for human observation. Emerging tenerals head up into the tree tops and are only rarely seen away from water.  

Second, they have very specific habitat requirements. Laura’s Clubtail,  only breeds in creeks and small rivers with clear water and sandy or rocky bottoms, within or close to heavily wooded areas. It’s challenging to observe odonates in some of these locations, and in Ohio, many of these water courses may not be publicly accessible.

Although the overall level of Odonata observation within Ohio has significantly increased since the launch of a new survey in 2016, mine is the only new location to be identified. I hope there are other breeding populations in Ohio and nearby states. Presumably, those locations—if they exist—are not subject to high levels of attention from those actively looking for Odonata and publicly recording their sightings.  

Much of Ohio has been "rewilding", which has been a boon for many species, but evidence suggests that this species doesn’t travel very far, inhibiting its ability to recolonize what may have been previous breeding areas. Confronted with significant habitat change and increasing climate change, this species’ sustainability in Ohio— and indeed in its entire range—remains an unanswered question.

 A pair of conservation organizations are planning to restore a channelized creek less than two miles away (as the dragonfly flies). I’ve been working to determine which odonate species are currently in the several hundred acres of associated property, much of which is also slated for some restoration. Who knows what species might choose to recolonize it?  Perhaps it would be a useful place to experiment with Stylurus relocation. In the meantime, my plan is to continue monitoring the creek in my own backyard, while encouraging other people to identify and explore new locations. 

*****

Jay Heiser recently retired as an IT Analyst at Gartner, where he was responsible for Cybesecurity research. He is the webmaster for the Ohio Odonata Society (www.ohioodonatasociety.org, and can be reached at jay@heiserhollow.net.