A slender silhouette, the Notonecte criss-crosses the waters of the pond, spinning towards the surface, where it stops for a brief moment, legs and abdomen brushing the mirror. As if posed on the air, in an inverted world.
The freshwater "bee" bug
An essential inhabitant of ponds, the glaucous notonect cannot go unnoticed, a small insect of 15 mm, regularly emerging on the surface, to come and breathe. Always in a characteristic posture, the back downwards, its back legs allowing it to swim vigorously. Aquatic bug, it crosses its cousins, the Ranatre and the Nepe. And is just as carnivorous, consuming its prey with its stinging-sucking rostrum. Among half a dozen species of Notonectinae in Europe, Notonecta glauca is certainly the most common. Its life is entirely aquatic, from the egg to the adult.
It lives underwater but breathes oxygen from the air
Like many aquatic insects, the Notonecte has kept an air breathing mode. Only the larvae just out of the egg breathe under water, through the integuments. As soon as they grow, they must go up to the surface of water and constitute a reserve of air. This will be done at the level of the elytra, semi-membranous upper wings, and the silks of the abdomen. The network of tracheas will thus be able to be supplied with fresh air during the periods of immersion.
Effective hunting techniques
Patient, the Notonectes can hunt on the lookout, waiting for an unwary prey. An efficient swimmer, equipped with vibration detectors, it can also launch into fast, precise chases, where it leaves little chance for crustaceans, insects, worms, and even tadpoles or small fish. Its front legs hold its meal, pierced by the stinging-sucking rostrum. A first channel will allow him to inject a salivary juice paralyzing and digestive. By a second channel it will absorb its liquefied menu.
A powerful vision
The effectiveness of the hunting techniques of the Notonecte is reinforced by a highly sophisticated vision. Its two large black eyes defy the laws of optics and allow it to see under water, on water and above water.
At the same time. The adaptation to its living environment, to the interaction of the aquatic world and the aerial world, is optimal. Posed on the surface of the water, back downwards, tips of legs and abdomen maintained by the surface tension, it watches. Any prey coming from the sky, stranded on the water, or swimming quietly, will be spotted. And consumed.
The backstroke swimmer
Its name describes its appearance, "nocto" meaning back, "necte", swimming. The notonecte splits the water with its belly upwards, its elytra carinated downwards. With its long back legs covered with bristles it propels itself with efficiency, its swimming is fast, incisive, with a jerky rhythm. Placed on the surface of the water in an inverted position, it paddles gently, attentive to the slightest vibration, the slightest movement. Efficient to move in aquatic environment, the Notonecte is much more clumsy on the ground, encumbered by its two long back legs. It prefers to fly away, deploying its two pairs of wings, and in a soft roar leave towards new ponds or ponds to colonize.
Males and females, aquatic meetings
Pairs of Notonectes are formed at the end of winter, after fertilization the eggs are laid in the tissues of aquatic plants. Small larvae emerge, similar to adults, but clear, soft, without wings and reproductive organs. They will evolve to their adult form in five successive stages, and will be ready at the end of the summer to hibernate. The very first heat will see them come to the surface, ready for a new reproductive cycle.
The Notonecte is one of the most present insects of the ponds. A calm water, plants, abundant preys, it will not miss the call. Easy to observe, it is however better not to touch it, its rostrum then becoming defensive and provoking sharp pains similar to bee stings.
