Damselflies belong to the suborder of Zygoptera with about 95 genera or groups of related species. The greatest diversity of damselfly species can be found in tropical regions, however, with the exception of Antarctica, these carnivorous insects live in a range of habitats such as grassland, forests, mountains and suburban areas worldwide. The essential requirement is freshwater -- temporary pools, streams, rivers, ponds, lakes, even waterfalls -- where the winged adults can lay their eggs.
The life span of damselflies varies between species and within species depending on environmental factors. After one to three weeks, the eggs, laid in water, usually hatch, releasing the larvae or nymphs, but eggs laid in late summer may overwinter before hatching. The nymph stage can last from two months to three years depending on the species, water temperature and food availability. They will develop quicker in warmer water and where food is plentiful. Life as winged adult damselflies is relatively short, with most living just a few weeks, although some species do live for several months. Most tropical species will have shorter aquatic stages and longer adult lives than temperate species.
The female damselflies lay hundreds and sometimes thousands of eggs attached to plants or floating debris such as wood just below or on the water's surface. Some species of damselflies can crawl down stalks and lay their eggs up to a foot under the water. After a few weeks, unless they over winter, the surviving eggs hatch and life as nymphs begins.
The aquatic nymphs have wide heads with slim green-brown bodies and breathe using three leaf-like gills. They mostly wait in the vegetation for their prey -- fish-fry, tadpoles, water beetles and smaller nymphs -- to come within striking distance. They also hide to avoid their predators, which include fish, beetles and larger nymphs. For two months to three years, depending on species and environmental conditions, the nymphs will eat and grow, shedding their skin 5 to 15 times before they are fully grown and crawl out of the water to emerge from their larval skins.
The pale colored young adults leave the area near water until they are ready to mate. They eat on the wing, feeding mainly on flying insects, and use flight to escape their predators, which include fish, birds such as swallows, frogs, lizards and small mammals. When mature, the damselflies will return to the water where they hatched -- some species find new locations -- and their long, thin bodies will now be bright blues, greens, yellows and reds with some browns and blacks. The males have claspers on their abdomens to hold onto the females behind their heads when they mate, while the females curl their bodies forward, creating a wheel shape, and this allows the reproductive organs to touch. After mating, some species fly in tandem, with the female bearing the weight of the male while she lays her eggs. Other species separate and the female lays her eggs alone, while some females are accompanied by the males flying close to them to ward off rival males. During the brief weeks of adult life, most females will lay several batches of eggs.
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