National Geographic : 1951 Aug
218 National Geographic Photographer Willard R. Culver Happy Ending of a Dragonfly Hunt: the Net Holds an Unexpected Tropical Species With his cyanide killing bottle held ready, the author retrieves the first specimen of Erythrodiplax umbrata found in upland Florida. Ordinarily it ranges from the West Indies to Argentina. This catch was made near Lake Stearns (page 224) by Richard Archbold (right). Didymops exchanges its old freckled skin for a new one brightly patterned in stripes of brown and yellow; shifts to the rear of its head the little nipple-shaped nymphal eyes, and sets in their place at the front two big green eyes shaped more or less like doorknobs. This marvelous change of form is made with out any intervening pupal stage; the develop ment is direct from nymph to adult. Anyone walking along the beach may see the empty skins clinging to tops of the tussocks in the morning, before the daytime breeze has risen to blow them down. Later he may find them battered in the drift line at the farthest reach of the waves. Transformation occurs at night, when most enemies are not abroad. By sunup the adult Didymops will have flown to the shelter of the woods. How long it is before they begin foraging, I do not know, but sooner or later they may be seen flying back and forth along the narrow roads through the scrub. They fly with foraging Sky Pilots and Anax, but more slowly, at a generally lower level and with longer resting periods between flights. Didymops's face is yellow, crossed by three broad bars of black; the body is dark brown, ringed with yellow; wings are clear, with yellow front margin; the long hair at both ends of the thorax is white. A familiar little dragonfly found all over the United States, and often abundant south ward, I call the Blue Back (Pachydiplax longipennis). It has a wingspread of about two and a half inches. Parallel stripings of yellow adorn its slender blackish body, and two short streaks of brown flash on a field of gold in the base of each hind wing. Prettiest in the early days of its life as an adult, while its yellow stripes are bright and clear, the Blue Back gets hoary with age, as we all do. The color pattern of the back later disappears under a powdery coat of uniform dusty blue. Blue Back Shows Friendliness The Blue Back perches low; flies mostly at the height of shrubbery; and selects prominent bare twigs on which to sit and watch the world go by. Like a kitten, it seems to want to be friendly. It may be observed at the short range of bifocal spectacles, if approached slowly enough and with very cautious ad vances. I have often watched a Blue Back thus for several minutes, while it sat stock still or merely tilted its eyes to pick up the news of the neighborhood. Blue Backs make short flights with long intervening pauses and are rather easily taken with an insect collecting net.