National Geographic : 1951 Aug
sect world and perhaps is more widely known than any other American dragonfly. In the clear, sand-bedded lakes of peninsular Florida lives a large dragonfly called Didymops (derived from the Greek for "double eye"). Its nymph is a flat-bodied, long legged sprawler upon the lake bottom. Outspread upon the sand, the nymph is quite un discoverable, for it sits im mobile and its camouflage is perfect. Its head bears a pyramidal, upcurving horn in front; and on each forecorner an eye whose tip, rising high above the general level, sticks up like a periscope through the thin ooze. The nymph does not chase its prey. It sits and waits for whatever providence may bestow, its huge grasping "mask" held in readiness for seizure of the food. In early spring the nymph becomes mature and moves slowly toward the shore, seek ing something on which to climb up out of the water for transformation. Often in the lakes of the Florida scrub the stems of maiden cane stand at the forefront of shore vegeta tion, but these will not do for the Didymops nymph; its body is so broad and the legs so far apart at base that it cannot climb single slender stems. Nymph Changes Directly to Adult It bypasses the cane and moves on to the tussocks of sedge that rise from the water nearer shore line. There the stems stand close and the nymph can encompass several with its feet. Drawing them together, it climbs up the tussock to find a place, a foot or more above the water, where it can attach the long, strong claws of its six feet. There it sheds its last nymphal skin and comes out a dragonfly. At first it is limp and pale, with stubby, crumpled wings; but it is ready for remodelling into a new elegance of form. For K 217 Richard Archbold Didymops Sheds Its Swim Suit for Brave New Wings During the night, when bird enemies were absent, the dragonfly emerged from its nymphal covering, which hangs like a discarded gar ment on the sedge stalks. Striped in brown and yellow, the matured insect pauses briefly before making its first flight at dawn. Middle and hind legs support the body. Forelegs, held over the head like horns, handle food and brush clean the bulging green eyes.