Acilius sulcatus

Common furrows float ( Acilius sulcatus )

The common furrows float ( Acilius sulcatus ) is a beetle of the family of diving beetles ( Dytiscidae ).

Features

Beetle

The beetles are 15 to 18 millimeters long. The chitin armor is primed yellowish. On the elytra has plenty of small black dots. On the pronotum are horizontally two broad black and in between a yellow stripe. At the top you can clearly see a black V- drawing between the eyes. The tag ( scutellum ) is dark. The outline of the body is oval without a clear discontinuation between the head, pronotum and abdomen, giving the beetle in the water a streamlined shape. The males have smooth elytra, are located in the females on these hairy longitudinal grooves. The antennae are filiform. The males wear on the front legs a large and about 270 small and on the hind legs 16 small suction cups, they are missing the females. On the hind legs can be seen long bristles, used by the beetle as a rudder for locomotion.

Larvae

The larvae are of elongated shape and the front ( forechest ) is very narrow, built back considerably wider. Full grown they reach body lengths of around 3 inches. The long, narrow 8 and the 7 Abdominalsegement each carry a wide hem of swimming hairs. The mandibles are short and dagger- shaped.

Similar Species

• Acilius canaliculatus. The common furrows between the eyes float has a distinct black "V" and before another black spot, which is pulled to the rear "V " shaped. In Acilius canaliculatus contrast, the black markings around the bright field between the eyes before only as a simple "V" back is showing.

Occurrence

The animals come across the Palaearctic, also in the far north, widely used before. They are often in small standing waters, some even to be found in puddles. They also live at high altitude.

Way of life

The beetles swim constantly and practically never rest. They prey on small invertebrates, which are crushed before the mouth. Since the animals need air to breathe, they have occasionally come to the surface. Once there, they renew their air reserves, which they wear in the water under their elytra with it. To search for new habitats, fly the beetle also across the country. During mating, the male holds using its suction cups on the front legs of the female. The females lay about 500 eggs in groups after 30 to 50 pieces of rotten wood, moss or on damp banks above the water surface. The larvae live similar predatory as the full-grown animals. The prey is digested, however, and sucked dry by the larva before the mouth. Pupation takes place above the water surface. From the dolls then slip the finished beetles.