Dancers along Bear Creek, California

On July 16th Leslie Flint and I joined Tim Manolis on an ode trip along Bear Creek. It's along route 20, west of Williams, and just past the junction where route 16 t-bones into route 20. The day started warm and reached 90+ when we quit at 2 pm. Not a place to go as a first-timer, or alone. Cell service non-existent and access to creekside habitats can be dicey.

We saw 20+ species of odes that day, including 15 dragonfly and roughly 5 damselfly species.

The three main genera of our Pond Damselfies (family Coenagrionidae) are the Bluets, Forktails, and Dancers. The Dancers, genus Argia, hold their folded wings above the abdomen, while Bluets and Forktails hold folded wings alongside the abdomen. Paulson informs us (Dragonflies and Damselflies of the West) that there some 111 species of Dancers in the world, of which 32 are seen in North America. We have 10 dancers in California (Manolis - Dragonflies and Damselflies of California). We tallied 4 of those along Bear Creek that day.

My favorites was Emma's Dancer, Argia emma. which we found along Bear Creek on the west side of route 16 on our way home. the male is a pretty light purple, with blue at the end of the abdomen at S-8-10. The 4 wings neatly overlap each other, which makes for less than clear venation patterns in a photo. Emma's Dancers are damsels of the northwest, extending down to Central California. Found mostly along rivers and large streams.

We found the Sooty Dancer, Argia lugens, at several locations. It's also a dancer of western states, but with a more restricted distribution than Emma's. The lack of color makes for less dramatic photos. Rounded forms on the bottom of S-2 may be water mites.

Another Sooty Dancer posed for a bit. Perhaps someone out there can tell us what the white bits hanging from the end of the abdomen are all about. The perch here may be on Dallis Grass, an invasive weed in wet areas.

Final dancer photo of the day is a marginal shot of what is likely a California or Aztec Dancer. The 2 species are quite similar and require close examination "in hand" by someone with a hand lens and strong experience for an accurate ID. Note how the abdominal segments are mostly blue, and how the black stripe on the side of the thorax is both slender and forked. Both Aztec (Argia nahuana) and California (Argia agriodes) are western species with considerable overlap in their distributions. Aztec's range extends well into Texas.

Lastly, I remembered that the Vivid Dancer, Argia vivida, was the first damselfly I ever photographed. This from a 2005 trip with Rich Stallcup to Mono Lake and points south.

Vivid Dancer - Argia vivida

Damselflies are a challenge, especially for a relative beginner like me. Young damsels emerge with soft bodies and weak wings, and are called tenerals. They're rather devoid of color and markings, so identification is difficult. The first 2 photos show a large tan teneral damselfy that we saw at Lake Lagunitas on Wednesday most likely a Vivid Dancer, with terminal appendages that suggest it might be a male. The young damsel flew weakly on glistening wings, moving 3-6' each time as if looking for a sunny spot in the dappled shade of the picnic area along the creek below Lake Lagunitas dam. Note how the 4 wings are held together above the abdomen, like a sail, a characteristic of the Dancers (Argia), wheres the Bluets (Enallagma) usuallt hold their folded wings lower, on one side or the other of the abdomen.

Teneral dragonflies are relatively devoid of color, but as the exoskeleton hardens color gradually appears, along with field marks that can make identification more positive. In the case of the Vivid Dancer the male will get a brilliant blue on the thorax and abdomen.  Details on the thorax are also helpful and include a think black dorsal stripe and a humeral stripe on the side that thins out or disappears at its midpoint.

 The female can be blue (andromorphic) or tan (gynomorphic), or other shades. The black markings are unique, with teardrop-shaped spots on the sides of the middle abdominal segments, as seen in this pair of Vivid Dancers in tandem position.