Dragonflies flying into the house also indicate family harmony. According to folklore, dragonflies are very clever. They only fly to families with harmonious families. Dragonflies don't go to homes where they often quarrel and get angry. Dragonflies really symbolize the harmony between husband and wife. It can bring more happy blessings and longer-lasting love to a harmonious family and make the family harmonious for a long time.
Dragonfly's antennae are short and bristle-like, and many receptors are distributed on them. The types of receptors mainly include cone receptors, cavity cone receptors, plate receptors and altar receptors. Studies have shown that different kinds of dragonflies have different kinds of receptors, and their number and distribution are also different.
There are also differences between male and female dragonflies. The receptors of female dragonflies are stable in the same family, genus and species, but there are obvious differences among different families and genera. Although the differences between different species in the same genus are very small, the differences between individual species are obvious, so the receptors of female dragonflies also have certain significance in classification.
Dragonflies are the insects with the most eyes in the world. Dragonfly's eyes are big and bulging, occupying most of the head. Each eye is made up of countless "small eyes". These "small eyes" are connected with photoreceptor cells and nerves and can distinguish the shape and size of objects. Their eyesight is so good that they can look up and down without turning their heads. In addition, their compound eyes can measure speed. When the object moves in front of the compound eye, each "small eye" reacts in turn, and the moving speed of the target object can be determined after processing. This makes them master insect catchers in the insect world.
Many dragonflies are brightly colored and are a large category of ornamental insects; Adult dragonflies often prey on agricultural pests such as moths, and the larvae of mosquitoes are also aquatic insects. Dragonflies can prey on mosquito larvae and adults respectively. Aedes aegypti is the main vector of dengue fever. An effective way to prevent dengue fever is to reduce the number of Aedes aegypti around human beings. Dragonflies are natural enemies of Aedes aegypti, and they have a strong ability to prey on Aedes aegypti. It is efficient and feasible to control the population of Aedes aegypti by controlling dragonflies, so as to prevent the transmission route of dengue virus.
Dragonflies generally live in wet places, such as dams or ditches. This living habit is mainly caused by its feeding method. An important medium for its reproduction is water, and its eggs are laid in water. Before an egg hatches, grows and becomes a formal dragonfly, it is carried out in water. So they are very dependent on water, and they need water more. If there is no water, they will not survive. If there is no water, they will become extinct.
In fact, all living things depend on water. Another reason is that dragonflies prey on mosquitoes, chironomids and other small insects, such as flies, bees and butterflies. Dragonflies prey on water because there are so many insects for them to eat.