Why do dragonflies skim the water? It turns out the dragonfly is laying eggs
Dragonflies are the collective name for insects in the dragonfly families Libellulidae and Aeshnidae of the order Odonata. Adults generally fly over ponds or rivers catching flying insects, while the larvae (naiads) develop in water, breathing underwater with rectal tracheal gills. They generally have to molt more than 11 times, taking 2 years or more before they crawl out of the water along aquatic plants, and then after a final molt they emerge as adults. Now let us take a look at why dragonflies skim the water!
Why do dragonflies skim the water?
A dragonfly skimming the water is a female dragonfly laying eggs. Dragonflies usually lay eggs on aquatic plants by small rivers and in ponds. After the eggs are laid, the larvae that hatch on the aquatic plants are called “shui chai” (dragonfly naiads). The naiad must live a long crawling life in the water, taking at least 1 year, or as many as seven or eight years, before it can emerge as an adult dragonfly. After emerging as an adult, its short, plump abdomen becomes increasingly slender and elongated, and the wings that were once folded together unfold one by one, finally turning into a dragonfly like a little airplane. It can be seen that “a dragonfly skimming the water” is a natural part of a dragonfly's life——laying eggs to reproduce and continue the species.
What are dragonfly larvae called?
Dragonfly larvae are called shui chai (naiads). When a dragonfly egg first hatches, it has a special form: the six legs and the head are all contracted against the body, like a little shrimp without legs. This stage is called the “pronymph stage”. The pronymph stage is very short, at least three to five seconds, and at most two to three minutes, after which the back of the pronymph splits open and the first-instar nymph molts out. Dragonfly larvae have different numbers of instars depending on the species. Generally, the younger the dragonfly larva, the lighter its body color. The time the entire larval stage takes varies with species and season, ranging from one month to three or four years.
What do dragonfly larvae eat?
To avoid natural enemies and catch prey, dragonfly larvae have body colors very close to their environment. Those usually inhabiting streams feed mainly on mayfly naiads, stonefly naiads, chironomids and other dipteran larvae, as well as some small fish. Species inhabiting still waters feed mainly on tadpoles, small shrimps, small fish, water fleas, smaller dragonfly naiads, backswimmers, mosquito larvae, chironomids and other dipteran larvae. The natural enemies of dragonfly larvae are birds, large omnivorous fish, Ranatra chinensis, Diplonychus rusticus, diving beetles and the like.