Dragonflies are a squad of flying predatory insects. Representatives of this group of animals are common in the tropics, subtropics and temperate regions. To date, about six thousand representatives of this detachment are known. These insects are characterized by an indirect method of development, which includes a transitional stage (dragonfly larva) and an adult stage (adult). Both larvae and adults are the basis of the diet of some fish species. What are dragonflies?
What do adults look like?
Before the dragonfly larva will be considered, it is necessary to learn more about the way of life of these insects. The adult is quite large, with a pronounced and moving head. The organ of vision is the huge facet eyes that occupy the entire upper part of the head. The body of the insect is elongated and consists of the thoracic and abdominal parts. The limbs of the dragonfly are not developed too much, but the bristles are located on them, which act as a hunting basket - this creates the opportunity to hunt in flight.
Representatives of this group have two pairs of wings that are almost the same size and are actively involved in flight.
What do dragonflies eat? As already mentioned, these are predatory insects. Smaller species become their prey. Mostly these are midges, mosquitoes and other insect pests. Dragonfly itself usually becomes food for fish.
Reproduction and development of dragonfly
These insects mate in flight. Developed copulative organs can be seen on the abdomen - in this way it is easy to distinguish between a male and a female. Another interesting feature is that the male removes foreign sperm from the female’s copulative apparatus before placing his own. A similar phenomenon has no analogues in the wild.
Then the female lays the fertilized eggs. As a rule, oviposition is carried out either in water or on aquatic plants and much less often in moist soil. From each egg, a dragonfly larva appears.
Dragonfly larva
The larvae of these insects live in water. Their body is painted olive brown. They breathe with the help of rectal gills and through the integument of the body. These creatures are inactive, but the way they move deserves attention. First, a portion of water is sucked in through the anus, which is then pumped out under high pressure from there. The recoil force pushes the insect in the opposite direction. In addition, the dragonfly larva can swim with the help of gill plates, which perfectly replace the fins.
Another feature of the larva is the presence of the so-called mask, which is represented by an overgrown lower lip. The mask plays the role of a grasping apparatus. Insects at this stage of development do not actively hunt - most of the time they sit at the bottom or attach to the aquatic plant, waiting for prey, which they then grab, quickly throwing the mask forward.
Dragonfly larva feeds mainly on daphnia, mosquito larvae and other insects. Before the last molt, the insect gets ashore and attaches to the plant. It is here that the larva transforms into an adult form - the imago.
Types of Dragonflies
It is worth noting that dragonflies are a fairly common group of insects. The detachment is divided into two main suborders:
- Damselfly Representatives of this squad have equal-sized pairs of wings. Due to this structure, a soft, fluttering flight is characteristic of insects. The larvae of such dragonflies live in flowing or standing water bodies.
- Damselfly dragonflies. These insects have two pairs of large, almost transparent wings. In a calm state, their wings are placed perpendicular to the abdomen. It is worth noting that representatives of this group are considered one of the fastest insects. Larvae live either in a pond or in a swamp.
It is interesting that experienced fishermen quite often and successfully use these insects as bait.