Velia caprai
Great Brook runner ( Velia Caprai )
The Great Bach runners ( Velia Caprai ) is one among the water striders iwS ( Gerromorpha ) belonging Bug (Heteroptera ). It resembles the closely related water striders in the narrow sense ( Gerridae ), but has much shorter legs than the representatives of the bug family. The insects usually live sociable on the surface of flowing waters where they mainly reside in the riparian vegetation and lurking on the surface of the water falling prey.
Features
The insects reach body lengths from 6.2 to 8.5 millimeters. The animals are usually wingless ( adapter ). Only 1 to 20 percent of individuals, mostly females, are langflügelig ( makropter ). They are black brown in color with bright red-brown and silvery spots on the upturned sides ( Connexivum ) of the abdomen. The similar kind Velia saulii with östlicherem dissemination focus is on the ventral side a row of black spots which may be absent, while Velia Caprai has a broad black stripes. Furthermore, the posterior tip of the abdomen edge is Caprai long and pointed undressed in the females of V., in the males short and pointed; with V. saulii these are short and blunt.
Dissemination
The Great Bach rotor is distributed from the British Isles and southern Scandinavia to the northern Mediterranean. In Central Europe the species is found everywhere, even in places frequently.
Way of life
The Great Bach runners usually live in groups in so-called schools are in which both the adult animals ( imagos ) and their larvae observed. They are diurnal and nocturnal.
The species has only few demands on the quality and the structures of their living waters. They settled smallest, fast flowing rivulets to slow flowing streams with low degree of contamination and not to heavy vegetation with water plants. Less commonly they are found in stagnant waters. They usually spend their time at the creek edges, by clinging to aquatic plants or other shore structures with legs. With quick movements, they will swim towards possible, passing swimming prey on the water surface. This grapple with the front legs and suck on the shore or on solid ground out. The species prefers to live in streams with randlichem wood species, but also occurs on woody plants free, non- shaded waters of the open countryside.
The animals hibernate as Imago or occasionally as Altlarve in the riparian vegetation. Depending on the geographic region of one or two generations are formed. If only one generation passed, the new adult animals appear from late July or early August, in two generations in June and in September. The females glue their elongated eggs lengthwise on the substrate, partially submerged on water plants, plants on land near water, in the water or floating objects in moss. This Wanzenart is one of the hardiest in Central Europe and is even in January you in freezing temperatures to actively take on the water surface.