Dragonflies are beneficial insects. They are carnivorous insects. They like to catch a variety of agricultural and livestock pests, such as mosquitoes, flies, small butterfly moths and so on. They belong to an important insect that is very beneficial to human beings.

At the same time, dragonfly can be used as an insect to detect environmental pollution. Dragonflies like to live in a humid environment and usually fly by the river or pond. Their larvae need to grow in water. Adult dragonflies usually lay eggs in the water, then catch other aquatic organisms, and then slowly climb out of the water to mate and lay eggs before emergence.

brief introduction

Aedes aegypti is the main vector to spread dengue fever, and dragonflies are the natural enemies of this mosquito, which have strong predation ability on Aedes aegypti. At present, the effective method to prevent dengue fever is to reduce the number of Aedes aegypti around human beings. Controlling the number of dragonflies and then controlling the number of Aedes aegypti is an efficient and feasible method to prevent the spread of dengue virus.

Dragonflies have an amazing appetite. A big green dragonfly, commonly known as "Qingtouleng", can eat nearly 3,000 mosquitoes a day. Hydra has not lost its "evolutionary body" at all, and can eat 2000 squid a year. However, it was later found that hydrangeas can be made into extremely delicious food, so they boarded the menu of human beings and became the object of capture, and the number dropped sharply, which also led to a sharp decrease in the number of dragonflies.