Friday, July 1, 2016

Western Red Damsel

For some time, I have been telling Scott King, my dragonfly guru, about the spring in the Koester Prairie (Prairie Creek Wildlife Management Area). This grassland is fairly pristine, and the spring runs all year. Scott said, “This sounds perfect for finding Rice County’s first record of the Western Red Damsel.” I had to agree, despite my seeing this damselfly only twice before. Red damsels love marshes. Their small size and their reluctance to leave the vegetation make these damsels hard to see.

We immediately found dozens of red damsels, male (upper photo) and female (lower photo). The taxonomy of these little creatures is a mess. Western Red Damsels are found in the western United States. Eastern Red Damsels are found in the east. Red damsels from Indiana to western Colorado and from southern Saskatchewan to Missouri and Kansas are intermediate in their field marks.

Three solutions exist for this problem.

1. Recognize three species.

2. Call Eastern and Western Red Damsels just Red Damsels, recognizing but one species.

3. Ken Tennessen studied this problem and reported to the Dragonfly Society of America. He concluded that there are but two species. Characteristics used to separate the two species include “the ratio of hind femur length to abdomen length, setal color, and hind femur color pattern.” Unfortunately, the abstract describing his work does not include details. Tennessen does write that the red damsels in Wisconsin are Eastern. But Hummel writes me (pers. com) that Tennessen identified Hummel's Iowa damsels as Western. Scott King tells me that all his Minnesota records are also of Western Red Damsels.

Without further input from the experts, comparing my photographs from those on the Internet, I suspect mine are Western Red Damsels. Note the white tips to the male’s abdomen. This color is obvious on Internet photos of Westerns. On the other hand, if my photos are of Eastern Red Damsels, I will add a new species to my Odonata list.

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