Bald-backed wood ant
| Bald-backed wood ant | ||||||||||
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Formica polyctena worker |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Formica polyctena | ||||||||||
| Forester , 1850 |
The bald-backed wood ant ( Formica polyctena ) belongs to the genus of wood ants ( Formica ), in the subfamily of scale ants (Formicinae). It is also known as the little red wood ant .
features
The head, mesosoma and stalk limb are predominantly colored red. The gaster and the top of the head are black. The cheeks and head shield are black-brown, as are the legs , which only have a reddish tint at the joints. The two black spots on the pronotum and mesonotum are blurred and often indistinctly recognizable.
This wood ant is only slightly hairy on the head and back, unlike the red wood ant ( Formica rufa ), with which it is very easy to confuse. It is often completely hairless on the pronotum or has a maximum of 15 bristles. On the underside of the head it has a maximum of seven short hairs and the limb of the stem has only individual protruding hairs.
While the queens and males can reach a body length of nine to eleven millimeters, the body length of the workers is four to 8.5 millimeters. The sex animals swarm between the end of April and June.
distribution and habitat
The bald-backed wood ant colonizes deciduous and coniferous forests of all kinds and also lives in pure spruce forests ; It appears numerous on sunny forest edges, but in contrast to the red wood ant ( Formica rufa ) it also penetrates deeper into the forest. The distribution area extends from Iberia to Lake Baikal . In Europe , the area extends from 42 degrees to about 61 degrees north latitude. In mountains it occurs at heights of up to 1,000 meters.
Way of life
Almost all nests are polygynous . Nests in which only a few or a queen live are very rare. In the spring the ants swarm. After mating, which immediately follows the swarming, the young queens have two options: they can go into a nest of their own species or found a new colony by invading a nest of the gray-black slave ant ( Formica fusca ), the Formica fusca -Kill queens and lay eggs yourself. When a colony has grown too big, "offshoot nests" form. These will remain connected to the "mother's nest" for a few years.
nutrition
The diet of Formica polyctena consists mainly of honeydew and insects , other sweet juices (e.g. nectar or tree sap) and plant seeds ( elaiosomes ) are also taken.
Nest building
The anthill is built around an old tree stump, but the nest base is underground. Building materials are needles and small twigs. The needle pile represents a heat store for the ants. The nest can reach a circumference of up to three meters.
Hazard and protection
The bald-backed wood ants and their nests are specially protected in Germany according to the Federal Species Protection Ordinance. According to the Red List of Germany, this species is not endangered.
literature
- E. Birk: The bald-backed wood ant in the Rudolfshagen nature reserve . Association magazine of the Deutsche Ameisenschutzwarte eV, Volume 9, Issue 3, Page 49; 1995
- Dieter Otto: The red wood ants . Westarp Sciences. 3rd, revised and expanded edition. 2005. 192 pages, 77 illustrations. ISBN 3-89432-718-9
Web links
- Formica polyctena inthe IUCN 2013 Red List of Threatened Species . Listed by: Social Insects Specialist Group, 1996. Retrieved October 9, 2013.
- Pictures of Formica polyctena at the German Ant Conservation Center
- Investigation of the strength of wood ants, especially the species Formica polyctena, within the framework of the project "Jugend forscht"
- Image of a group of bald-backed wood ants
- Article in the AmeisenWiki
