On June 14 we walked the trail around the pond and spotted a number of male Chalk-fronted Corporals, mostly in open sunny areas not far from the water. The males are distinctive, with a light blue waxy coating (pruinosity) on the top of the thorax and the proximal abdominal segments. The wings are quite plain, in contrast to many more ornate species in the skimmer family (Libellulidae).
I enlarged the above photo to show the base of the wings where they join the thorax, to show small black areas with some adjacent brown color., the only markings on these otherwise plain wings, but all the better to show off the venation.
After some searching I finally found a Chalk-fronted Corporal perching briefly on some vegetation near the water.
The Corporals, genus Ladona, are a small North American genus sometimes placed with the King Skimmers, Libellula. There are 3 species of Corporals, but this in the only one whose range extends to Northern California.
For esoterica-inclined souls (you are probably one if you read this far), the rank of corporal has an insignia of two bars. I figured that referred to the 2 broad white bars on the top of the thorax as seen above. Then I read that the use of "corporal" for this genus refers rather to the 2 narrow bars on top of the thorax seen in females and immature of the genus, and not to the broad white bars in these photos, which actually do look like a corporal's bars. I was still puzzled, as the top of the thorax is clearly not the "front", so why call it chalk-fronted? Well, turns out that the "top" here is also the "front", as it refers to the part of the thorax in front of the wings! Go figure.
Give me a simple name like Exclamation Damsel any day.
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