Lasius umbratus

Yellow shadow ant ( Lasius umbratus )

The Yellow Shadow ant ( Lasius umbratus ) is an ant from the kind of garden ants ( Lasius ) in the subfamily of ants scales ( Formicinae ). You will be counted in the subgenus Chtonolasius.

Features

The species of the subgenus Chthonolasius as workers are very difficult to distinguish from each other, individual workers are often indeterminable. A reliable determination is possible primarily on the basis of the Queens. Therefore, Wilson took on all kinds of the group as only one variable species.

The animals are, like all related species, light yellow to brownish yellow in color with relatively small eyes, and short Maxillartastern which covered not reach the back of the eye rim. The body surface is covered by a dense, pubeszenten hair and works by the shimmer. In this way, the hair is a little raised and seem a bit confused stored. Between the pubescence long, thin, erected hairs are embedded, and on the underside of the head. The top of the scale ( between fuselage section and Wi abdomen) above is sharp, her upper margin is nearly straight, or slightly cut.

Distribution and habitat

The species is widespread Palaearctic, it occurs in Europe, North America and throughout northern Asia, in Asia it is less common than related species. It is common in Central Europe and lives eg in sparse forests, in moist grasslands, in gardens and along roadsides. Together with Lasius mixtus she is the type of the subgenus, which penetrates into rather damp and cool habitats most. They settled quite well strongly anthropogenically influenced habitats. So they occasionally within houses ( in basements ) ago. She avoids only extremely dry and very wet habitats. Lasius umbratus usually feeds mainly on the excretions of subterranean, root -sucking aphids and scale insects ( trophobiosis ). But it is a generalist and can exploit other food sources.

Like all Chthonolasius species is in this kind of a temporary social parasites. Important for the settlement of young queens is therefore the presence of suitable host nests.

Yellow shadow ants are capable, floods survive by concatenating the individual animals with their bodies at a bivouac raft.

Reproduction

The females swarm, together with the males between late June and late September, to sultry afternoons until the early hours of the night in and try after they have mated near the parent colony to find a host nest as soon as possible. As hosts, serves mainly the black ant ( Lasius niger). Other, lesser known host species are the brown garden ant ( Lasius brunneus ), Lasius emarginatus, Lasius psammophilus. Before entering the host colony the young queen kills first a worker from the host species, to provide for the transfer of the nest specific fragrances to their own surface. The dismembered remains for a while carried in the mandibles, which facilitates apparently also the deception of the members of the host colony. Thus, the penetration into the host cavity is possible. After the successful penetration of the parasitic queen is more attractive than the host queen, who eventually dies from neglect or is expelled from the nest (described by Gößwald on the related Lasius mixtus ). The penetration into the host nest is risky and beats very often fail, succeed, particularly in very small nests. After establishing the queen lays eggs that are raised by the host workers. After these are extinct, the colony is later continued with their own workers.

Lasius umbratus itself is also host of other social parasites. The Shiny Black wood ant ( Lasius fuliginosus ) they used the same way as the host ant in their colony founding.

Swell

• Bernhard Seifert: determine to observe ants. Nature Publishing, Augsburg, 1996. ISBN 3-89440-170-2