As we walked along the trail that circles Picture Lake, we saw a number of dragonflies and damselflies. I'll tell you more about them later, but for now I want to focus on one particular dragonfly that turned out to be quite interesting.
At one point we noticed a Ringed Emerald fly to a pine tree and land in the bright sun. As I approached the tree, however, I noticed another dragonfly that was already perched in the same tree, just a few inches away from the emerald. It was a darner, and it was perched deep in the shade of the tree—which is unusual for the darners I'm familiar with, even on a hot day. I realized it was an interesting species because it had simple appendages and blue spots on the tenth segment of the abdomen. I got a few pictures before it flew off, and looked forward to doing some research on them when I got home.
Here's the darner perched in the tree:
After doing a bit of research I realized I had a Sedge Darner, the first of that species I've seen. The simple appendages, blue on S10, and bold thorax stripes all point to that species.
One additional field mark stood out, however—the yellow dorsal stripe on S2. That was quite unexpected. You can see it a bit better in the following enlargement:
I've checked other photos of this species, and the yellow dorsal stripe seems to be a reliable field mark for this species. Here's a photo from the University of Puget Sound of a Sedge Darner specimen:
Here's a different specimen from the same collection:
Other photos online also show this feature, though none of the field guides mentions it at all. Just one more interesting case to add to the various dorsal stripes on S2 that have been pointed out previously in this blog.
Subarctic Darners also have yellow dorsal stripes on S2, but their thorax stripes are quite different from those on the Sedge Darner.
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