From spring to autumn, the damselflies come to brighten up the pond, twirling between the rushes, typhas and sedges. Experienced pilots, they chase their prey in full flight, putting in place astonishing amorous parades. Then they disappear at the beginning of the winter, leaving their aquatic larvae to survive the bad season.
An international reputation
The Damselflies stand out among the insects of wetlands by their colorful hues, metallic blue, fire red, straw yellow, bright turquoise ... Their four finely ribbed translucent wings are often shaded with the colors of the body.
At rest, they fold like a book along their fine and graceful body. Characteristic differentiating them from their cousins the dragonflies, keeping them well spread out, in horizontal position.
Damselflies, also called Agrionians, Zygopterans, are classified among the Odonates, hundreds of species exist around the world, all leading a half aquatic, half aerial life, the young growing underwater, as larvae.
A half aquatic, half aerial life
At their birth, the small larvae of Odonata have an entirely aquatic life. They must therefore breathe under water. In damselflies, three gill lamellae of variable shape can be observed at the end of their abdomen, depending on the species. Folds near the rectum also play a role in gas exchanges.
After several successive moults the larvae will leave the aquatic environment and will have to adapt to an air breathing. A network of fine tracheae runs through the body of the damselflies, bringing the air as close as possible to the cells.
Fearsome predators
Damselflies, both larvae and adults, have effective and deadly hunting techniques. The larvae, brown to gray, go unnoticed on the muddy bottom. Especially since they do not move. They wait. Eyes, antennas, sensitive bristles, on the alert. If a prey passes at a distance that seems to maintain a certain but illusory security, it deploys a lip mask. At great speed. And catches small insect larvae, crustaceans, worms... The victim is crushed, swallowed. The mask then folds under the head, "masking" in certain species a part of their face. To leave towards a new hunting territory, the larva moves on its six legs and undulates with its gill lamellae, which act as fins.
Hunting pilots
Adult damselflies have nothing to envy to their young. They hunt in flight. Mosquitoes, butterflies, mayflies, flies, all small insects are potential targets. Their big round eyes, well detached, spot any movement. Fast, with their four wings, they melt on their preys, capture them with their front legs, bring them to their mouth, crush them before swallowing them. During the summer season, they fly all over the world, regulating many human pests.
Males and females, aerial meetings
In spring, real ballets begin above ponds, puddles and streams. The male Agrions locate their territory, watch it, invite a pretty partner. They delicately seize her by the neck, from the end of their abdomen. The female thus maintained will bend to bring the end of her own abdomen towards the penis of the male. This one being located at the beginning of the abdomen, it follows a figure of speech evoking a heart. And the eggs are ready to be fertilized.
A laying under close supervision
The fertilized damselfly decides to lay eggs. Under the close supervision of her partner. Depending on the species, he will hold her by the neck during the whole operation. Or he will stay close to her to ensure a close protection. The laying, dozens of eggs, will be made inside the plant tissues, under the leaves of water lilies, along the stems of rushes, cattails...
The first larva will leave its plant hole, and will quickly take the long and fine aspect of the larvae of Zygoptera. Several moults will follow one another during several months, even several years according to the species, to reach the size of transformation into winged adult. The larva then climbs on the plants, tears its old envelope, deploys and dries its wings and its new body before taking its flight.
