These colorful insects are very beneficial because they feed on mosquitoes and gnats. They also feed on bees, some butterflies, wasps and other insects. There are two categories the damselflies and true dragonflies that are usually found in temperate and tropical swamps and streams. Dragonflies have large heads with bulging eyes, short antennas and strong jaws. They are very colorful and are seen in many varied colors of yellow, green, blue. Some have spots or stripes and are easily seen on dark backgrounds. They have a very long slender abdomen behind a very short thorax with three sets of legs. Their veined wings are attached to the thorax and are translucent. They are equipped with two sets of wings, which allow them to fly forward, backward or sideways and because their wings rotate and can move up or down. The dragonfly can pursue its prey in flight using all six legs to catch and hold onto their prey while crushing them with their jaws. Dragonflies usually stay within a few miles from where they emerged from their eggs when hatched. In their early stages, they are larva and feed on small fish and tadpoles, and are carnivorous in both the larva and adult stages.
Dragonflies lay their eggs in water, by dropping them directly into the water. The eggs take between two and three weeks to hatch. The larva also known as a naiad has internal gills for breathing, and they remain in this stage for about three years. When the time is right, they crawl out of the water, shed their skin and become a dragonfly, the life span of the adult dragonfly is about one year. The dragonfly dates back to pre-dinosaur some 250 million years ago with a wingspan of about three feet this is the largest dragonfly recorded. There are about 3600 species of dragonflies around the world at this time. Dragonflies are large compared to other insects; some have as much as a six-inch wingspan. They are very agile when flying and are noted as being among the fastest insects, however, their wing muscles must be warm to function properly, which is why dragonflies are often seen resting in the sun or beating their wings to generate heat in order to fly. Most of the time they seek out smaller insects. However, they can consume prey who weighs about sixty percent what they weigh.
Damselflies though not a true dragonfly is often mistaken as a dragonfly. They are much smaller and more delicate than the true dragonfly. They hover above the reeds and grass of smaller ponds where they live off the insects they catch. While the Damselflies rest, they place their wings directly above their bodies. They lay their eggs on the soft plants just under the water's surface. Like the dragonfly, they pass through the same aquatic life span by hatching from an egg, spending a couple of years in a larvae state, finally crawling from the water where they shed their skin one final time becoming an adult Damselfly.
The mating posture for the Dragonfly and Damselfly are the same the male and female twist themselves into a wheel-like position as sperm is transferred, they can be seen flying together with the male pulling the female behind by clasping onto the back of her head. A few of the species remain in this tandem position until the females lay her eggs.
In the larvae state, both the Dragonfly and the Damselfly breath through gills that are found in their rectums, they live on mosquito larvae, tadpoles and small fish. If they need to get away they can quickly propel themselves away by expelling water through their anus. Some naiads can even hunt on land. Dragonflies though one of the fastest flying insects in the world does not do well walking, and they often fall prey to birds, water bugs, lizards, spiders, frogs, and larger fish.