Wolf spiders

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Wolf spiders
Alopecosa sp.

Alopecosa sp.

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Partial order : Entelegynae
Superfamily : Lycosoidea
Family : Wolf spiders
Scientific name
Lycosidae
Sundevall , 1833
Eye area of ​​a Hogna type

The wolf spiders (Lycosidae) are a family of spiders within the superfamily of the Lycosoidea and currently comprises 124 genera with more than 2443 species . (As of April 2019)

The wolf spiders also include the harmless " tarantulas " (formerly Tarentula ; today mainly included in the genus Alopecosa ). With a few exceptions, wolf spiders do not capture insects through fishing nets, but rather lie in wait for them. The enlarged rear median eyes, which are arranged directly in front, are noticeable. The sense of sight is important for hunting and courtship in them , but not as well developed as in jumping spiders . With their very strong chelicerae (jaw claws), the larger specimens can also penetrate human skin. However, the amount and concentration of the poison is insufficient, even in the largest specimens, to severely poison a person.

Way of life

Supervision of a wolf spider in the living tube

The larger wolf spiders ( Arctosa , Trochosa , some Alopecosa ) native to Central Europe , like most species of this family, inhabit burrows in the ground, which they line with spider silk from the inside , similar to the wallpapering (Atypidae) or trapdoor spiders (Ctenizidae). Most of the other native species live in the herb layer or between stones, where they create webs of living space.

At night they leave the hiding place and go hunting: They wait in favorable places for an insect to come by. The wolf spider leaps forward from a few centimeters away and seizes the prey.

Members of the genus Pirata and Piratula prefer to be close to standing water. They run on the smooth surface of the water without sinking and hunt insects on the surface of the water.

Reproduction

Wolf spider defending its egg cocoon
Dark wolf spider ( Pardosa amentata ) with an egg cocoon
Dark wolf spider with young animals

The male wolf spider approaches the female ready to mate with the front pair of legs raised. The male can probably smell the willingness to mate from a distance of one meter. The courtship behavior is also triggered when threads of a female ready to mate are found. The male of Lycosa rabida vibrates with the abdomen on the substrate, then it performs circular movements according to a fixed pattern with the pedipalps , in which the seed pockets ( bulb ) are located. This movement turns into an audible "palp drums", which is generated by a stridulation organ .

During a break, the female willing to mate responds with a knock on the front legs and walks a few steps towards the male, which then starts the courtship movement again. This goes on until both are almost touching; the first contact is reserved for the female. If the other person is mistakenly also a male, the courtship is immediately answered with a threatening stilt. With nocturnal species acoustic signals play a bigger role, with diurnal species the optical ones.

The male crawls from the front onto the female and first bends down on one side of the abdomen to introduce the first palpus. The female aligns her abdomen accordingly. Then the second palpus is introduced from the other side.

In Rabidosa punctulata , a weak male has an evolutionary advantage if it latches onto a copulating couple. You save energy and protect yourself from cannibalism by the female.

Brood care

Wolf spiders (Lycosidae) care for their brood. The egg cocoon is attached to the spinnerets ( pardosa ) by the wolf spiders when hunting or carried on the abdomen (water hunter, pirata ) in order to be able to defend it from enemies. The egg cocoon is vigorously defended. If the cocoon is taken away from the female, objects similar to the cocoon, for example paper balls or small snail shells, are carried around.

The female helps the young spiders to hatch by biting the cocoon. The young immediately climb onto their backs. While up to a hundred small wolf spiders cling to the mother's hair, often sitting in several layers on top of each other and feeding on her egg yolk, the mother roams around, presumably to find the best possible microclimate conditions and good hiding places. In order not to expose herself to great danger, she refrains from hunting during this phase, which lasts about eight days.

You can even “slip” an alien cocoon under a female wolf spider, which she will also take care of. The hatching young then climb onto the stepmother and let themselves be carried around.

Systematics and taxonomy

With almost 2450 species in 124 genera, the wolf spiders are among the largest spider families in the world. In the eponymous genus Lycosa Latreille, 1804, more and more large spider species from all over the world have been united in the past 200 years, which then often had to be relocated to their own genera. Even today it turns out that hardly any of the 225 species included in the genus Lycosa seems to be really closely related to the type species Lycosa tarantula . This genus is considered polyphyletic and further, particularly biogeographical and molecular biological studies, should bring more clarity into the phylogenetics of this spider family.

Native species (selection)

Genera and species native to Europe are, for example:

Genera

The World Spider Catalog currently lists 124 genera and 2443 species for wolf spiders. (As of April 2019)

literature

  • Rainer F. Foelix: Biology of the Spiders , Thieme, Stuttgart 1979, ISBN 3-13-575802-8
  • Dick Jones: The Cosmos Spider's Guide. Over 350 Central European spiders and harvestmen , Franckh, Stuttgart, 1990, ISBN 3-440-06141-8

Individual evidence

  1. ↑ a b Natural History Museum of the Burgergemeinde Bern: World Spider Catalog Version 17.5 - Lycosidae . Retrieved November 11, 2016.
  2. ↑ Sex in three saves weak males from death . Hamburger Abendblatt of March 8, 2017, p. 20
  3. ^ Anton A. Nadolny, Alireza Zamanil: A new species of burrowing wolf spiders (Araneae: Lycosidae: Lycosa) from Iran. Zootaxa, 4286, 4 pp. 597–900, July 2017 doi: 10.11646 / zootaxa.4286.4

Web links

Commons : Wolf spiders (Lycosidae)  - Collection of images, videos and audio files

Lycosidae in the World Spider Catalog