Are dragonflies beneficial insects or pests? Understanding their true identity in one article

Dragonflies are typical hemimetabolous insects, divided into the two families Libellulidae and Aeshnidae. In the stage of transformation from nymph to adult, they do not go through a pupal stage. In their entire life they go through only three stages: egg, nymph and adult. The nymph is aquatic, while the adult is a terrestrial insect with the ability to fly. Let us take a look below at whether dragonflies are beneficial insects or pests!

Are dragonflies beneficial insects or pests?

Dragonflies are beneficial insects. Dragonflies are hemimetabolous insects. The nymph, called a "naiad", lives in water, breathes in the water through rectal tracheal gills, and hunts using its highly developed labial mask. It generally has to go through more than 11 molts, and needs 2 years or more before it climbs out of the water along aquatic plants, and then after a final molt emerges as an adult. In the water, the nymph can prey on mosquito larvae or other small animals, and sometimes members of the same species also cannibalize one another. Both adults and larvae are carnivorous and mostly eat pests. Besides being able to prey on large numbers of mosquitoes and flies, some adults can also prey on pests such as butterflies, moths and bees, so they are truly beneficial insects.

How long can a dragonfly live?

The dragonfly's larva, the naiad, must spend at least one year in the water. The time required for the entire larval stage varies according to different species and seasons, ranging from one month to three or four years, and those that take longer must endure seven or eight years before they can emerge as adults. The lifespan of the adult dragonfly is only one tenth that of the larva, living only about one month to eight months; even so, among insects the dragonfly still counts as long-lived.

Why do dragonflies skim over water?

A dragonfly skimming over 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 "naiads". The naiad must live a long crawling life in the water, at least 1 year, or at most seven or eight years, before it can emerge as an adult dragonfly. After emerging as an adult, its short and fat abdomen becomes increasingly slender, and the wings that were originally folded together unfold one by one, finally becoming a dragonfly like a little airplane. It can thus be seen that "dragonfly skimming over water" is a natural part of a dragonfly's life -- laying eggs to reproduce offspring.