Thursday, July 19, 2012

Lyre-tipped Spreadwing

Most local spreadwings are nearly impossible for the amateur field observer to identify. Perhaps that is why I neglected to post these photographs last year. The male on the top photo was taken along the Sakatah Singing Hills Bike Trail in La Sueur County on 3 August 2011; the female in the lower photo was taken in Erika's garden in Northfield, Rice County, on 19 July 2011.

Using Damselflies of the North Woods as a guide (this book should cost around $20 rather than the $200 quoted by Amazon), I believe these are Lyre-tipped Spreadwings. (Scott King also helped a bit.) The white on the back of the male's head, the three gray, terminal abdominal segments, and the relative clarity of the wings all support this identification. Furthermore, the male's paraprocts (central spines poking out the middle of the rear of the abdomen--between the longer cerci at the rear edges) appear to be curved. Although my guide warns "separation of females of these species...is tentative," the greenish stripes on the abdomen's top are indicative of this species. The guide concludes, "positive identification is based on subtle differences in lengths of some abdominal segments seen under a microscope."

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