Aedes vexans

Aedimorphus vexans, Aedes vexans former name

Aedimorphus vexans ( sometimes referred to as " Rheinschnake " ) is an almost globally widespread mosquito and the most common of the species occurring in Germany the mosquito family. It is the only species of the genus represented in Europe Aedimorphus that was formerly counted as a subgenus to the large collection genus Aedes.

From their way of life here she is counted among the " flood mosquitoes ". Because of their breeding range in flooded lowland forests and meadows, this vast mass of nature is there as well as other common species of mosquitoes such as Ochlerotatus sticticus, Aedes Aedes cinereus rossicus and addressed as a meadow or floodplain forest mosquito mosquito. Their mass distribution is encountered at various locations through targeted biological pest control.

Features

Adult animals of Aedimorphus vexans reach a length of about 6 millimeters. Your body is brown to golden brown. The trunk and the short palpi are dark scaly, with a few bright scales on the tip of the palpi. The back and the pointed abdomen have light gray to whitish scales, form the B- shaped pattern. The tibiae are above dark and light on the bottom. The tarsi of the hind legs have at their ends to thin white bands.

The body of the larva is divided into the head with mouthparts, eyes and antennae, three fused thoracic segments and nine abdominal segments. On the eighth abdominal segment sits a powerful breathing tube with a tuft of hair in the middle or slightly above the middle. The larvae hang with the breathing tube at the water surface at an angle upside down. The shape of the breathing tube can be used to differentiate the various species of mosquitoes.

Occurrence

Aedimorphus vexans is distributed almost worldwide and is found in the Holarctic, the Oriental, Mexico, parts of Central America, in the Transvaal region, and on some Pacific islands.

Way of life

The Aedimorphus males gather in the evening, with high humidity or in heavily shaded forest territories in the afternoon, often several thousand mosquitoes comprehensive dance swarms. The located about 2 meters up and down moving males produce by the wing beat a artcharakteristischen buzz that attracts the females. These are taken and mated in flight. After mating, the female makes in order to suck blood. This is the further development of the eggs absolutely necessary. Per day, the mosquito lays it stretches up to a total of up to 10 kilometers back. The females of terrain island hike to terrain island, so areas with favorable for them living conditions, particularly high humidity in which they survive the dry heat of the day. In addition to the active migration, it also happens that swarms are carried away by the wind over long distances. After the blood meal, in which the female mosquitoes have taken about twice their body weight, these are the proteins contained in blood use within 5 days to build up your eggs ( ovulation ). A female can form with a meal up to 100 black oblong oval, spindle-shaped 0.7 mm x 0.2 mm large eggs, which places them individually in moist soil of meadows and riparian forests. The eggs are heavier than water, so do not swim. After the plug-in mosquito can produce more eggs without copulation if they can receive a blood meal.

Add the eggs develop within an embryonic phase of about 8 days, the larvae. These hatch out only when the egg membrane is by a flood in deoxygenated water with more than 10 degrees temperature. The lack of oxygen after the change in the water causes the contraction of a muscle, the Schlüpfzahn - a sharp hardened mandrel head - pressed against the egg membrane. The egg membrane then breaks up at a pre-marked spot. The cap of the spindle-shaped ice flakes off and the embryo can slip out. Oxygenated water inhibits the Slips actuator, which may represent a protection against fish that from ending up in the flow of oxygen-rich water. In addition, the strong current would the larvae drift away. If a flood from which eggs can survive for at least three years.

About four larval and a pupal stage the larva developed for mosquito. Depending on the water temperature it needs for 1 to 3 weeks, the pupal stage lasts 2 to 4 days.

Relevance to humans

Aedimorphus vexans spread through their bites depending on the area several diseases such as Tahyna, myxomatosis, encephalitis and Dirofilaria immitis. In the highly water-rich summer months it comes to water bodies such as the Elbe, Danube and Lake Constance, but especially on the Rhine to the mass- occurrence as with any other of mosquito. Among the 33 occurring in the Upper Rhine mosquito species provides Aedimorphus vexans over 80 percent of individuals. In one square meter of shore area of a flood pond Aedimorphus 50,000 eggs can be detected not rare.

Along the Upper Rhine have been because of the mosquitoes plague, mainly because of the massive emergence and highly migratory readiness of Aedimorphus vexans, joined nearly 100 municipalities on municipal work for the control of mosquitoes plague and fight with a larvicide based on proteins from the bacterium Bacillus thuringiensis israelensis the development the mosquitoes.

System

The genus Aedimorphus belonged to 2009, as a subgenus of the genus Aedes.

In the eastern Palearctic subspecies Aedimorphus vexans nipponii ( Theobald ) was described, which differs from the nominate form by a different scales on the terga and Pleuriten.

Documents

• Norbert Becker, Dusan Petrič, Marija Zgomba, Clive Boase, Christine Dahl, John Lane, Achim Kaiser: Mosquitoes and Their control. Springer, 2003, ISBN 9780306473609, pp. 201-203.
• Norbert Becker, Paul Glaser, Hermann Magin: Biological mosquito control in the Upper Rhine, ( Festschrift ) 20 years Municipal Action for the control of mosquitoes plague, ISBN 3-00-000584-6 1996