European Bach-like
| European Bach-like | ||||||||||||
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Image of a European Bachhaft |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Osmylus fulvicephalus | ||||||||||||
| ( Scopoli , 1763) |
The European brook-like insect ( Osmylus fulvicephalus ), formerly also called water ant lion maid , is the only representative of the brook-like insect family found in Central Europe . It occurs in natural waters with an intact floodplain landscape.
features
The Imago has a body length of up to 18 millimeters with a wingspan of 44 to 48 millimeters. The head is strikingly orange-brown in color and has thread-like, around nine millimeters long, black antennae . The compound eyes are also black. The wide wings are crystal clear and have a variable pattern of black and some white spots, which are largely homonomous and not connected to one another. In the resting position, the wings are laid out like a roof on the body. The veins of the wings have fine bristles and are structured like a net. The legs are colored light yellow-brown. The males have a pair of scent glands at the end of their abdomen between the 8th and 9th abdominal segment, which can be everted.
The elongated eggs are quite large at 1.7 millimeters and are light gray in color. They have a raised, white micropyle on the long side . The young larva saws open the egg shell with an egg tooth.
The three larval stages are all similarly shaped and 3.5 to 16 millimeters long. They wear very long, barely curved suction tongs. These are paired and lance-shaped and are composed of the upper and lower jaw. Fine saw teeth sit at the tip. The jaws lie one above the other so that a suction channel remains open in the middle. On the back of the larva are rows of bristles on chitinized humps. The legs also have pointed bristles. On the 10th abdominal segment there is a pair of retractable adhesive devices with eight rows of pointed chitin hooks. In this way, the larvae hold on when they threaten to be pulled away by the prey.
The doll is quite similar to the body shape of the Imago. When hatched, the doll's skin opens on the back. The head is the last to leave the doll's shell.
Synonyms
Frequently used synonyms up to the 20th century are:
- Hemerobius chrysops Sulzer, 1776
- Osmylus maculatus Fabricius, 1787
Occurrence
The European Bachhaft is common in practically all of Europe and in Anatolia . However , they are rarely found on the Iberian Peninsula and the Apennine Peninsula . The adults live from May to July in heavily overgrown, shady areas with rich structures in flowing water. They are sometimes found in large numbers. In Central Europe they can be found from the lowlands up to an altitude of about 1,000 meters.
Way of life
The adults predatorily feed on other bank insects such as mayflies . During the day they sit on the underside of leaves or fly over the water or in the bank thicket.
Mating and development
For mating, dark areas such as bridge passages on the stream are sought out. The males attract females with the excretions of their scent glands. Mating begins in the afternoon: the couples sit next to each other at right angles and tease each other with their antennae. At night they sit down parallel, the male grasps the female with the mandibles on the hips ( coxae ) of their front legs. The female pulls a spermatophore from the sexual opening of the male with the end of her abdomen . This actual act of copulation takes between five and 80 minutes.
The animals develop for a year. The eggs are laid on the underside of bank plants, especially on moss, near the ground or on stones to eight to 27 pieces in a curved row. A female lays around 60 eggs in total. The larvae hatch after two to three weeks. These live on the shore on the edge of shady waters under stones and between bank plants. The animals also penetrate below the surface of the water, but they have no gills and cannot swim. With the help of air bubbles in the foregut they can save themselves to the surface of the water. In the interior of the forest, they can sometimes be found on the edge of rain puddles. The diurnal larvae are predatory and prefer to hunt insect larvae that are not very agile, such as those of mosquitoes , nymphs and pupae. When grasping the prey, the mouthparts are thrust into the prey and then opened like scissors to hold the prey in place. The venom of the pine glands then paralyzes the prey.
Hibernation takes place in the second or third larval stage under moss and leaves. They tolerate prolonged flooding. In spring they molt to the third larval stage and from the end of April they pupate in moss or damp soil in a whitish cocoon . The cocoon construction takes two to four days, the pupa rest 10 to 14 days.
literature
- Johannes Gepp: The Bachhaft Osmylus fulvicephalus 240 years after its description by Johannes Antonius Scopoli - Austria's Insect of the Year (Osmylidae, Neuroptera). In: Carinthia II. 193/113. Volume, Klagenfurt 2003, ISBN 3-85328-030-7 , pp. 324–334 ( PDF on ZOBODAT ).
- E. Wachmann , C. Saure: Netzflügler, mud and camel neck flies, observation, way of life. Naturbuch Verlag, Augsburg 1997, ISBN 3-89440-222-9 .
Web links
- Osmylus fulvicephalus in Fauna Europaea
- Photos on BioImages