The dragonfly, with wings outspread,
May rest upon a flower,
Or travel through the sunlit air
At many miles an hour.
His relative, the damselfly,
Has colors just as bright.
He holds his wings above his back
When resting from a flight.
SMALL children often call dragonnies "darning needles" or "snake doctors." Dragonflies look ferocious, but they do not sting or bite as many small flies do. As they fly swiftly over the water, or dart here and there above the cat-tails along the lake shore, they snatch mosquitoes and other little flies out of the air and eat them. You will always know true dragonflies because
they hold their wings stiffly out at their sides, even when at rest.
The smaller flies which hold their wings over their backs when they alight, and which
you may have taken for smaller dragon-flies, are called damselflies. They are close relatives of dragonflies but are different in several ways. Damselflies are dainty creatures with long, slender bodies and delicate wings. Their forewings are about the same width as their hindwings. Dragonflies are much larger, with heavier bodies and broader wings. Both damselflies and dragonflies live in fresh water when they are young. Before they become adult flies, they are called nymphs.
The dragonfly nymph, sometimes called the water dragon, will probably be among the first animals you collect. His lower "lip" is very large and folds in the middle. If you turn him over you can see this. In the photograph which illustrates this chapter, you can see this lip stretched out, and you can also see it folded up on the under side.
When a little animal comes close, the dragonfly nymph shoots out his lip and draws it back very quickly, as if it were hinged. All you can see is a jerk, but the dragonfly nymph has captured his victim
and swallowed it. We should be grateful to him for the many mosquito larvae he eats. Snails and all kinds of insect nymphs and larvae also serve as food for a hungry dragonfly nymph.
You will not see gills on a dragonfly nymph, as you did on the mayfly and the stonefly, because they are inside the opening at the end of his broad abdomen. He slowly draws water into the gill chamber through strainers which guard the opening. Oxygen from the water passes into the gills and is carried through his body in respiratory tubes. Then the water is forced out again very quickly. This sends the nymph forward in short, jerky movements.
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