Are dragonflies beneficial or harmful?

Dragonflies are typical incomplete metamorphosis insects, which are divided into two families: Dragonidae and Odonidae. From juvenile to adult, there is no need to go through the process of pupation. They only go through three stages: egg, juvenile and adult. The juvenile is aquatic, while the adult is a terrestrial insect with flying ability. Let's take a look at whether the dragonfly is a beneficial insect or a pest.

Is dragonfly a beneficial insect or a pest?

Dragonflies are beneficial insects. The dragonfly is an incomplete metamorphosis insect. The juvenile "Shuizhi" lives in the water, breathes through the rectal trachea Gill and preys with a very developed face cover. It usually takes more than 11 times to molt, and it takes 2 or more years to climb out of the water along the aquatic plant, and then molt and feather into an adult. Young worms can prey on wigglers or other small animals in the water, and sometimes the same kind also eat each other. Both adults and larvae are carnivorous and eat more pests. Adults can not only prey on mosquitoes and flies, but also prey on butterflies, moths, bees and other pests.

How long can dragonflies live?

The larvae of dragonflies take at least a year to stay in the water, and the whole larval stage varies according to different species and seasons, ranging from one month to three or four years, and those who take longer have to endure seven or eight years before they can emerge as adults. The life span of adults of dragonflies is only 1/10 of that of larvae, and they can only live for about one to eight months. Nevertheless, dragonflies have a long life among insects.

What is the purpose of scratching the surface?

The female dragonfly is laying eggs. Dragonflies usually lay their eggs on aquatic plants in small rivers and ponds. The larvae hatched on aquatic plants after ovulation are called "water flies". Water flies have to crawl in the water for a long time, at least one year, or seven or eight years before they can become adults of dragonflies. After feathering into an adult, the short and fat belly becomes more and more slender, and the previously folded wings spread out one by one, and finally become a dragonfly like a small airplane. It can be seen that "dragonfly scratching the surface" is a natural part of dragonfly life-laying eggs to reproduce.