Filigree Skimmers Are Back

Back in July of 2014, I documented a single male Filigree Skimmer dragonfly, Pseudoleon superbus, for the first time in Colorado. I am happy to report that there now seems to be a viable population of this species in the exact same location as previously.

Considering that there was tremendous upheaval at this site when an enormous water line was laid right through the stream (perpendicular, but buried), I am amazed that any aquatic life survived, let alone prospered. The water level has been substantially lower since the installation of the pipeline, but that doesn't seem to bother all the resident Odonata, including Flame Skimmers (Libellula saturata), another rather uncommon species here.

Female Filigree Skimmer

I visited the site on both July 5 and July 7. I arrived around ten-fifteen in the morning the first day, just in time to see a female Filigree Skimmer ovipositing (laying eggs), while at least one male flew erratically around her. Females of this species hover over the water and dip the tip of the abdomen into algal mats, laying at least one egg with each thrust. She quickly finished, paused on a rock for a few seconds, long enough for me to get four images, and then vanished. I never saw her again that day and I stayed a good while.

Meanwhile, the male stayed, flying around one of the ponds and periodically flying up and down the stream corridor, which is bound by a narrow, high-walled canyon, albeit a diminutive canyon. As the day heated up, he assumed the posture known as "obelisking," whereby an overheated dragonfly sticks its abdomen straight up in the air to minimize the body surface it exposes to the sun. It is the dragonfly equivalent of a headstand.

"Obelisking" male Filigree Skimmer

Upon returning home later that day, I informed one of our local dragonfly gurus of my finding, and he promised to visit the next day, July 6. He had tried to find the one in 2014, but to no avail. I honestly thought that if I did not get corroboration, that entomologists everywhere would think I was crazy. Happily, that was not the case then, and it isn't now because my friend found the male this time around. He notified another dragonfly authority who was supposed to come visit the site on July 7, but I did not see him there.

American Rubyspot damselfly

A bonus of my walk through the canyon on July 5 was spotting a male American Rubyspot damselfly, Hetaerina americana. This is not an uncommon species here around fast-flowing streams, but it was the first one I have seen in city limits. The "canyon" is at best a series of ponds these days, so this damselfly may want to find more dependable habitat.

Downstream canyon where I found the Rubyspot

I got to the site a little earlier on July 7, and only found a single male Filigree Skimmer initially. As the sun rose in the sky, illuminating more of the area, he became more active and was, to my surprise, eventually joined by another male. They literally chased each other all over the place. It was rather amusing to watch. I even managed to get a picture with both specimens in the shot.

Two males!

Then, about ten-thirty AM or so, here came the female again. She seemed to materialize out of thin air, went about laying more eggs, paused again for a photo op, and then "poof!" She was gone as quickly as she had arrived. I am told that the males will chase females long distances, but she did not appear to have any escort, at least this time. Her wings are so heavily mottled, and her body so cryptic, she could have landed somewhere close and virtually melted into the landscape.

Our Colorado friends should keep an eye out for this species even farther north, in appropriate habitats: Rocky canyons in mostly arid locations.

Filigree Skimmer State Record for Colorado

Earlier this month, on July 3, I was fortunate enough to be in the right place at the right time to make an important observation and documentation of a male Filigree Skimmer, Pseudoleon superbus, in Colorado Springs. This represents the first confirmed state record for the species as well as a significant northern range extension.

There is a vast series of vacant lots up the hill from my home that includes a narrow, deep riparian corridor through the otherwise degraded shortgrass prairie habitat of the hills. The channel carries water dependably throughout the year, and trickles into Sand Creek, a wide, mostly dry riverbed that sometimes runs in very shallow, meandering rivulets (except during storms when the volume is much greater).

The Filigree Skimmer was frequenting the large pond shown in the habitat shot above, repeatedly perching on the rockwork between forays up and down the watercourse. At first I assumed it was probably a Common Whitetail, Plathymis lydia, but something about those wing markings looked a bit off. Noting where it was repeatedly perching, I worked my way into a position where I could get the images shown here, taken with a Canon Powershot SX50. That powerful zoom sure comes in handy at times like this.

The near pristine condition of the specimen makes me wonder if perhaps the species does breed here rather than migrate up from the species' usual range of southern and central Arizona, New Mexico, and western and central Texas. This is essentially a subtropical species found as far south as Costa Rica, though mostly in dry uplands there.

Male specimens have the wings mostly blackish, especially the hind wings. Females have much less black, arranged in an abstract, reticulated pattern. Both genders have the "pinstripes" on the eyes. The total body length varies from 38-45 millimeters, and the length of the hind wing averages 30-35 millimeters.

The preferred habitat for the Filigree Skimmer is a rocky stream or river with a slow or moderate current, usually in an open setting. The little creek where I found it certainly fits the bill. Females lay their eggs by hovering and dipping the tip of their abdomen into the water, usually in the vicinity of algal mats or piles of detritus. There is plenty of both in this location, too.

Bill Maynard, our local authority on Odonata, asked for directions to the spot where I saw the skimmer, and he visited on July 4 but had no luck. Ironically, he did observe several species of damselflies that I had not yet documented for the area. He also got a lovely image of a Gulf Fritillary butterfly, as likely to be seen this far north as the Filigree Skimmer.

My record of the Filigree Skimmer is awaiting confirmation at Odonata Central. I encourage my readers to consult that website to see what species have been recorded in their state or county, and add their own observations as they deem appropriate.

Just because you have "never seen this (insert name of insect or other arthropod here) before in (your) life," and you have "lived here for (insert number of decades or years)," does not mean that it is something rare or exotic or otherwise novel. BUT, sometimes it really is a unique find worthy of note. That is your take-home lesson for today: Be observant and don't assume anything. It helps me to have some knowledge of what should and should not be here in Colorado, but you, too, can make significant contributions to our collective scientific knowledge.

Source: Paulson, Dennis. 2009. Dragonflies and Damselflies of the West. Princeton, New Jersey: Princeton University Press. 535 pp. I highly recommend this reference, well worth the price.