Gaster (hymenoptera)
As Gaster (from ancient Greek γαστήρ (Gaster) = abdomen, stomach) is referred to in apocrita (Apocrita), so the Hymenoptera with "wasp-waist", the more or less bulbous rear (distal) portion of the abdomen , of the internal organs of the abdomen contains. Depending on the species, it begins with the second, third or fourth segment of the abdomen.
The constriction ("wasp waist") in the waist wasps only apparently separates the abdomen from the thorax . In fact, it lies between the first abdomen segment, which is fused with the thorax to form the mesosoma , and the second abdomen segment. The part of the abdomen separated from the mesosoma is called the metasoma . In some species, the first segment (e.g. some digger wasps ) or the first two segments (in knot ants ) of the metasoma are formed as a stalk ( petiolus ). There can therefore be further constrictions, behind which the uniformly convex or spindle-shaped narrow part of the abdomen begins. This rear (distal) part is called the gaster .
The grammatical gender varies in technical language . Both feminine and masculine are common: the guest or the guest .
literature
- Bernhard Seifert: Ants: observe, determine. Naturbuch Verlag, Augsburg 1996. ISBN 3-89440-170-2 : pp. 10-16