Dragonflies (Order Odonata)
These familiar insects are among the most beneficial of wetland insects. Often called "mosquito hawks," they feed on mosquitoes, midges, black flies, and other small insects. Dragonflies use their great speed and agility, plus excellent eyesight, to capture their prey in the mid air. All are harmless to humans. Females lay eggs in the water which hatch into wingless aquatic nymphs. The nymphs feed on insect larvae, worms, and other small creatures, and many remain underwater for several weeks, or several years, depending on the species. Dragonfly nymphs are, in turn, an important food for many game fish. The last nymphal stage crawls from the water, the outer skin splits and the winged adult emerges. This process of development is called incomplete metamorphosis.
The smaller, slimmer damselflies have a similar life history, but unlike dragonflies, they fold their wings over their backs when perched.
Digital Dragonfly Museum (Texas A&M University, Texas Agricultural Experiment Station)