Bembix rostrata

Centrifugal wasp when closing the burrow

The specially protected centrifugal wasp ( bembiX rostrata ) is one of the most prominent grave wasps in Central Europe. The genus is bembiX world with over 340 species, particularly rich in species in Australia and Africa, distributed, especially in heat areas with open, sandy soils. BembiX rostrata is the only way of Germany, in southern Central Europe, there is another type ( bembiX tarsata ).

Dissemination

The distribution of centrifugal wasp ranges from Europe and the Mediterranean to Central Asia. To the north she goes to Europe to Denmark and Sweden. A distribution area in Germany is the Rhine valley. From Brandenburg are increasingly facing new evidence, while it was no longer observed in Westphalia since 1960. Overall, a sharp decline in bound to dry warm sandy areas species is found in Germany.

Features

The German name derives from their special behavior in front of the nest. The animals dig with synchronized and rapid movements of their forelimbs their bottom tubes. Also, they can very quickly turn around their own axis, the wing beat of a buzzing sound, similar to a gyro makes. It is characterized by its size, the clear yellow and black abdomen drawn and extended to a narrow beak upper lip.

Way of life

The 15 and 24 -millimeter animals occur in colonies of a few dozen up to several hundred animals in which to create the females in open sandy soils, respectively, up to 20 centimeters deep tube containing only one brood cell. Equipped with dozens of insect is this, mainly larger flies ( Tabanidae, Syrphidae ), which serve as food for the larva her about two weeks of development to the imago. The Niströhre is closed again carefully after each feeding. Due to intensive brood care can a female in the middle of summer by bringing only a maximum of eight larvae. Centrifugal wasps are very site faithful, they often nest for years in the same places, even if they change over time and are evasive biotopes available.

In particular, the decline of larger open sandy areas to heat areas such as on the sand dunes of the Upper Rhine Graben, the centrifugal wasp has made rare. In addition, however it also has natural enemies, particularly parasites, such as Bombyliidae, Conopidae and Mutillidae. A parasitoid that specializes in centrifugal wasp wasp Parnopes is Grandior.

Already the great naturalist Jean -Henri Fabre has caused the behavior of the centrifugal wasp to intensive studies.