Tuesday, May 21, 2013

Hudsonian Whiteface (Leucorrhinia hudsonica)

Two or three pairs of eyes are better than one, and it's fortunate that I had a friend along on this particular nature photography hike, else I would have completely overlooked this small odonate. When he said there was a red dragonfly sitting along the trail I was somewhat skeptical ... in a couple more months the meadowhawks will be flying, but a red dragonfly this early in the year?

Nonetheless, the Hudsonian Whiteface does indeed have an overall red aspect, and the dorsal streaks extending to S7 on the abdomen are key identifying features – the only other species of Leucorrhinia in our area similarly marked (but not in red) is the immature male Dot-tailed Whiteface. In seven years of nature study and photography this is my first and only encounter with this small dragonfly.

At a length of about 30 mm the Hudsonian Whiteface is about the same size as our other local Leucorrhinia species (there are three others – the Dot-tailed Whiteface, the Frosted Whiteface and the Belted Whiteface).

A lateral view of the dragonfly: the sides of the thorax are marbled black and red. The hamules indicate that this is a male, and the shape is correct for Leucorrhinia hudsonica.

A dorsal and oblique view of the terminal appendages – I was somewhat remiss because I should have also taken ventral shots of the epiproct, because its profile is important in separating the different whiteface species.

However, enough of the trailing edge of the epiproct is visible in this oblique view that we can safely say it belongs to a Hudsonian Whiteface.