Red wood ant
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Red wood ant ( Formica rufa ) |
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| Formica rufa | ||||||||||
| Linnaeus , 1761 |
The red wood ant ( Formica rufa ) belongs to the genus of wood ants ( Formica ) in the subfamily of scale ants (Formicinae).
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 distinct black spots on the pronotum and mesonotum are out of focus.
The red wood ant is much more hairy on the underside of the head and on the pronotum than the bald-backed wood ant ( Formica polyctena ), with which it is very easy to confuse. She has at least 30 bristles on the pronotum and at least ten long hairs on the underside of the head. The stalk member is hairy on the side.
The body lengths are nine to eleven millimeters for the queen , 4.5 to nine millimeters for the workers and nine to eleven millimeters for the males. The sex animals of this species swarm between May and June, a little later than those of Formica polyctena .
The red wood ant is characterized by its powerful mouthparts . When attacking, the wood ants bite their enemy and inject acid into the wound. You can even drag larger animals - such as a dead mouse - to their nest together.
distribution and habitat
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They colonize well-sunlit areas on the edge of the forest of deciduous and coniferous forests of all kinds. They penetrate deeper into the stand less often and avoid shady spruce forests . This species of ant is distributed from Iberia to Lake Baikal and is also found in Asia Minor and the Caucasus . In Europe, the range extends from 40 degrees to 63.5 degrees north latitude.
Way of life
The red wood ant usually forms large polygynous colonies and colony groups comprising several nests. But there are also peoples known that remain monogynous for several years . In a laboratory experiment, evidence was found that the red wood ants have a magnetic sense.
food
The red wood ant feeds mainly on insects , larvae , caterpillars and arachnids as well as on carcasses and also on honeydew of leaf (Aphidoidea) and scale insects (Coccoidea). But she also likes to take the juice from trees and fruits. It contributes to the spread of myrmekochoren plants like the larksporn , because it is attracted by the scents of its oily seed appendages ( elaiosomes ) and carries their diaspores into their nests as appropriate food. It eats the oily seed appendages and carries the seeds out of the nest again.
Nest building
A rotten tree stump is searched for to found the nest, and in the following weeks a pile of tree needles, small branches and moss (fine material) is gathered. The litter peaks consist predominantly of spruce needles. The piles can reach an extension and height of up to three meters. The brood is carried around by the workers in the spacious, storey-like corridor and chamber system of the hill, depending on the need for warmth and moisture, so that no mold develops.
Reproduction
In March the queens lay their large eggs in the nest. From these later female sex animals with wings hatch. These animals are fed by the workers with special feed that the workers who hatch later no longer get. If a queen is to emerge from a larva, she receives a special lower lip salivary gland secretion. In the first few days, the hormones in the feed decide whether the larva will become a worker or a queen. A short time after hatching, the new generation's wedding flight begins. After this, the mated females begin their search for a burrow. They either colonize existing nests or establish a new one together, depending on auxiliary ants. Only when a generation of workers has grown up does the queen only lay eggs. When mating, the female receives seeds for her entire life, which are kept in a seed bag. When laying eggs, the female can fertilize the eggs herself and workers develop from them, or she lays unfertilized eggs from which the males hatch. Like all wood ants, it overwinters without their developmental stages, that is, during the winter rigor there are only queens and workers in the nest.
Division of labor
In the ant colony there is a pronounced division of labor. You can find different forms of ants, which are adapted to their respective tasks. The most numerous are sterile forms of ants without wings, the workers. An ant colony also has a few hundred fertile females - the queens. Winged males can be seen in June. They mate on a wedding flight. When mating, the queen receives a supply of sperm that will last for around 20 years. Since the males no longer play an important role for the ant colony, they are driven out of the state and die after a short time. The queens strip their wings at predetermined breaking points and return to their nest.
Hazard and protection
The Red Wood Ants are listed as Low Risk (Near Threatened) by the International Union for Conservation of Nature IUCN in the 2009 edition of the Red List of Threatened Species .
They and their nests are specially protected in Germany according to the Federal Species Protection Ordinance and are on the warning list (Category V) according to the Red List of Endangered Species in Germany. Individual countries in Germany assess the situation differently. The hazardous situation diverges between “not endangered” and “endangered” up to inclusion in a warning list. Switzerland rated them in the Red List of Endangered Species / 1994 edition as potentially endangered (category 4).
literature
- Dieter Otto: The red wood ants . (3rd, revised and expanded edition.) Westarp Sciences 2005; 192 pages, 77 illustrations, ISBN 3-89432-718-9
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Karl Gößwald : The wood ant
- Volume 1: Biological Basics, Ecology and Behavior . Aula-Verlag, Wiesbaden 1989, ISBN 3-89104-475-5
- Volume 2: The wood ant in the forest ecosystem, its use and protection . Aula-Verlag, Wiesbaden 1990, ISBN 3-89104-476-3
- Wolfgang Schwenke : Ants. The scented state . Landbuch-Verlag, Hannover 1985, ISBN 3-7842-0309-4
- Helgard Reichholf-Riehm: Insects. 1984, Munich
Web links
- Pictures of Formica rufa at the German Ant Conservation Center
- Formica rufa in the endangered Red List species the IUCN 2009. Posted by: Social Insects Specialist Group, 1996. Retrieved on December 28 of 2009.
Individual evidence
- ↑ Yilmaz Ҫamlitepe and David J. Stradling: Wood ants orient to magnetic fields. In: Proceedings of the Royal Society B. Volume 261, No. 1360, 1995, doi: 10.1098 / rspb.1995.0114 .
- ↑ Appendix 1 of the Federal Species Protection Ordinance
- ↑ Online query of the red wood ant in the red list of endangered animals in Germany and its federal states. science4you, accessed February 12, 2010 .