Black ross ant
|Black ross ant|
Black horse ant ( Camponotus herculeanus )
|( Linnaeus , 1758)|
The black horse ant ( Camponotus herculeanus ) is a species of ant from the genus of the horse ants ( Camponotus ). It is one of the largest ant species in Central Europe .
Previous authors have considered the three species C. herculeanus , C. ligniperda and C. vagus as breeds of one species. Appearance and way of life are very similar, but C. vagus only occurs in warm regions (in Germany so far only in Hesse , Rhineland-Palatinate and Baden-Württemberg ). C. ligniperda prefers the plains with dry pine forests on sandy soils, while C. herculeanus is more found in the mountains with moist soils and spruce forests. Mixing up the species in the overlapping areas is likely to be frequent, as it is often difficult for experts to identify them on individual animals.
The body length of the workers is 6 to 14 millimeters (mostly 9 to 12 millimeters). The ant's legs and scales are dark red while the head is black. The gaster is also black, but often with a dark red spot around the turn of the stalk ( petiolus ). Compared to the brown-black horse ant ( C. ligniperda ), the extremities such as the jaw palpation , the legs and the antennae are shorter, which makes the body appear more compact.
The black horse ant is a boreo-alopine species and is circumpolar . In Europe it can be found from Lapland to southern Europe , although in the south it only populates the mountain regions. But even in the central distribution area it is only present locally below 300 m above sea level. The species is only found in forests, where shady and moist populations are preferred, but in higher mountain areas it can also be found in open terrain.
Way of life
Although the ant lives in the wood and gnaws through it with corridors, it is not used as food. The statements about food are contradictory. It is assumed that this consists mainly of honeydew . There are also individual observations that buds and young shoots are gnawed and the emerging sap is absorbed. Other reports deal with predatory food acquisition. Here, the escaping body fluid is absorbed after cutting the prey cuticle and the proteins contained therein are split in the midgut.
The black horse ant builds its nests mainly in the wood of healthy standing trees. The spruce is preferred, and occasionally the pine. Hardwood is only populated in rare cases. The colonization usually happens after previous damage to the trunk, e.g. B. through damage to the back , but also through roots. In addition to pure "wooden nests", which are created exclusively in the wood, there are also often so-called "earth nests", which are at least partially in the ground. In contrast to C. ligniperda , the wood portion of the nests seems to predominate in the black horse ant and they extend further upwards in the trunk with a vertical extension of 6 to 10 m. Often several trees are integrated into the nest of a colony; Nest areas with up to 30 trees on 130 m² are possible. The sub-nests in the trees are in contact through underground connecting roads, which are preferably laid out along strong roots.
The nests are built in the heartwood and the sapwood is spared. Any chambers in the sapwood become resinified by the tree and become uninhabitable. As a result, the tree's water and nutrient channels remain intact and the tree continues to live. The regular characteristic structure of the nests arises from the fact that only the soft early wood is gnawed out in the annual rings and the hard latewood remains as a framework. The nest resembles hollow cylinders standing inside one another, in which the hollow spaces in between are used as passages and chambers.
The entrances to the nests are often hidden in the root area of the trees. Sometimes they can be recognized by the wood chips that have been removed, but often by the impact of woodpeckers. Most of these come from the black woodpecker , whose special diet is the horse ant. In order to get to the ants and their larvae, they have to chisel deep holes in the trees. Depending on the size of the nests, several holes are made, up to 17 holes have been observed in a trunk.
Processed wood is usually only colonized if it is in contact with the ground. This often happens with wooden buildings in the mountains.
Damage caused by nest building
Although the ants' activities do not kill the nesting trees, the black carpenter ant is considered a pest in forestry . On the one hand, it devalues the lower valuable trunk end and, on the other hand, it makes the trees more susceptible to wind breakage . The number of infected trunks in a stand should usually be only a few percent, individual reports of 20% infestation in an 82-year-old spruce stand are the exception. In general, however, there is no control, as the extent of damage is considered to be tolerable in most cases.
Sometimes the ant colonizes built-up wood. In particular, hunting lodges and log cabins in the forest are at risk. In these cases, control is necessary.
Propagation and colony formation
The wedding flight of the black ross ant takes place from May to June. Per nest, 2 to 5 main swarms can be expected, which begin 130 to 70 minutes before sunset at an outside temperature of 20 to 26 ° C. The males start swarming. The subsequent departure of the females is stimulated by the release of a mandibular gland secretion. Copulation takes place in the treetops. After successful mating, the females shed their wings and look for a hiding place (often under stones) and begin to lay eggs.
- Karl Escherich : The forest insects of Central Europe, Volume 5: Hymenoptera ( hymenoptera ) and Diptera ( two-winged winged ) . Delivery 2, Parey, Berlin 1942, pp. 466-471, DNB 992012821 .
- Bert Hölldobler : The social behavior of the male ants and its significance for the organization of the ant colonies: Investigation on Camponotus herculeanus L., Camponutus ligniperda Latr. and Formica polyctena Foerst. Würzburg 1966, DNB 481483276 (Dissertation University of Würzburg, Faculty of Natural Sciences, February 4, 1966, 122 pages).
- Wolfgang Schwenke (Hrsg.) Among others: The forest pests of Europe , Volume 4: Hymenoptera and Zweiflügler . Parey, Hamburg 1982 (pp. 278-282), ISBN 3-490-11416-7
- Wolfgang Schwenke: Ants. The scented state . Landbuch, Hannover 1985, ISBN 3-7842-0309-4
- Bernhard Seifert: Observe and determine ants . Naturbuch, Augsburg 1996. ISBN 3-89440-170-2
- Jiří Zahradník : Bees, wasps, ants , translated from the original Czech manuscript by Jürgen Ostmeyer (= Kosmos-Naturführer ), Franckh, Stuttgart 1985, ISBN 3-440-05445-4 .
- ↑ Bert Hölldobler and Ulrich Maschwitz : The wedding swarm of the horse ant Camponotus herculeanus L. (Hym. Formicidae). In: Journal of Comparative Physiology. Volume 50, No. 5, 1965, pp. 551-568, doi: 10.1007 / BF00355658