Yellow dragonfly - a frequent visitor to lakes and swamps
The family of real dragonflies unites more than 1 thousand species. Its representatives are found everywhere except Antarctica. Some of the oldest amphibious insects are active predators. Among the most common species is yellow dragonfly. Its hunting grounds are shores of lakes and swamps, where many mosquitoes are found. Growing larvae takes place in the aquatic environment. They leave the ponds in order to become a beautiful winged hunter on land.
View description
Dragonfly yellow or yellowish (lat. Sympetrumflaveolum) refers to the order of dragonfly, a genus of squeezed bellies. The species got its name due to golden yellow spots on the wings. The body of insects consists of three main departments: head, chest and abdomen. The dragonfly is 33-35 mm long, its abdomen is a significant part of the body - 22-25 mm. The head is large, mobile, the main part is occupied by complex faceted eyes. The special structure of the organ of vision provides the insect with an overview of almost 360 °.
Sexual dimorphism of insects is pronounced in their color.
Male
The chest is red-brown, at the rear edge of the fringe of long hairs. Long segmented abdomen of red color. The underside of the abdomen is black; on the extreme segments, a dark coloration occupies almost the entire surface. The upper part of the eyes is brownish red, the lower part is gray. The color intensity increases with age, and finally sets by the time of puberty.
Female
Chest yellow-brown with black stripes at the seams. The abdomen is yellow; longitudinal black stripes pass on both sides. Eye coloration similar to males. Bright yellow spots are visible at the base of the hind wings and the upper part of the anterior.
Dragonflies have a powerful gnawing oral apparatus with strong jaws and sharp teeth. The lower lip is larger than the upper and more developed. This structure allows dragonflies to chew prey on the fly. The segmented antennae are short and hardly noticeable. The limbs are made up of 5 main parts. Spikes are visible on the hips and legs. The legs are weak, they are designed to hold the body in place and catch prey. Spiked bristles help create a prey basket from the extremities.
Habitat
Yellow dragonflies are a common and numerous species. Its habitat is a large part of Europe, Siberia, the Far East, the Caucasus, and Central Asia. Insects are found on the shores of lakes overgrown with grass or swamps. In southern Europe, settles in flooded meadows, temporary lakes that dry up in the summer.
Lifestyle
The summer time of dragonflies is from late July to mid-September. They are active in fine sunny weather. In the afternoon, insects fly far from the coast. For the night they climb into the dense thickets of grass. Males select sites near shallow bodies of water with stagnant water. She aggressively guards her hunting grounds from the invasion of rivals. The ban does not apply to females. They can safely cross the established boundaries of the plots.
Yellow dragonflies, like other representatives of the family, have earned the fame of unsurpassed aerial hunters. Statistics speaks about the skill of insects - dragonflies catch 95% of the intended prey. They have no food cravings. All targets of suitable sizes are considered as prey. In the diet of predators flies, mosquitoes, butterflies.Damselfly dragonflies easily maneuver in the air, are able to dive at a selected object.
Interesting fact. Yellow dragonflies willingly sit on a man’s outstretched hand.
Dragonfly breeding
Mating of insects occurs in the air. The genital organs of females are located at the end of the abdomen. The male sperm outlet is located on the tenth segment of the abdomen, and the secondary copulative organ on the second. The structure of the reproductive organs of the male is unique. Before mating, he pumps sperm into the secondary copulative apparatus. During the mating flight, the abdomen of the female is bent to it. With special anal appendages, the males catch the partner by the neck and hold them during fertilization. The pair creates a closed figure in the air that does not fall apart thanks to the virtuoso technique of flight.
Fertilized females masonry in several ways:
- drop eggs on the fly into the water from a small height;
- lower the abdomen to the surface of the reservoir;
- throw eggs into moist soil or grass near the shore.
The average number of clutches is 300-500 eggs; they have a rather high mortality rate. Survival depends on temperature, the degree of contamination of the reservoir, the number of predators. Eggs laid in the fall develop for several months.
The larva of the yellow dragonfly when leaving the egg is only 2 mm. They are adapted to life in water, for the breath there are gills. Body color olive brown. The lower lip has become a grasping organ called a mask. Wing rudiments are clearly distinguishable, they increase after each molt.
The larval development cycle takes a whole year. During this time, they survive 7-8 links. The offspring of yellow dragonflies are extremely viable, they survive the freezing and drying of the reservoir, and are loyal to pollution. At first, they stay closer to the bottom or thickets of plants to hide in case of danger. Larvae eat crustaceans - daphnia, cyclops. As they grow older, they attack fry, tadpoles, and water bugs.
Information. Larvae await prey in an ambush, grab it with a mask and chew it with strong jaws.
A larva of the last age is selected from water on coastal plants. Here she is waiting for the skin to dry and crack. A young dragonfly appears from the discarded shell. It takes 20-30 minutes for the soft wings to straighten and harden. The color characteristic of the species appears after a few days.
Yellow dragonflies actively reduce the number of mosquitoes and flies on land and in water bodies. Insects are of great benefit by killing species dangerous to humans.