Blue Scarlet Dragonfly - Crocothemis nigrifrons FAMILY LIBELLULIDAE - Skimmers
Check these pictures: The Libellulidae family of dragonflies covers the skimmers that do not fit into either the emerald or cruiser families.
Both male blue dashers and male pondhawks have blue abdomens. The picture on the left shows a dragonfly with a blue abdomen. Which is it, a dasher or pondhawk? Knowing that pondhawks also have a green nose and thorax eliminates them from consideration. Knowing that the male blue dasher has a white nose and yellow stripes on the thorax suggests that the dragonfly in the picture is a male blue dasher.