Libellula pulchella (twelve-spotted skimmer) - note the pair of dark marks on the abdomen just below the wings. This is a male and the pruinosity (powdery blue color) was rubbed off when he mated. The female had gripped him at that point, scraping off the chalky color - From the Fauna Project at the Lady Bird Johnson Wildflower Center in Austin, Texas. Photo by Val Bugh.