Alpine grinder

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Alpine grinder
Alpine Volesus (Arctosa alpigena), male

Alpine Volesus ( Arctosa alpigena ), male

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Family : Wolf spiders (Lycosidae)
Genre : Voles ( Arctosa )
Type : Alpine grinder
Scientific name
Arctosa alpigena
( Doleschall , 1852)

The Alpine Wühlwolf ( Arctosa alpigena ) is a spider from the family of wolf spiders (Lycosidae). The species is represented in the Palearctic and, contrary to what its common name suggests, its range extends far beyond the Alps .

features

With a body length of 6.7 to 9.3 millimeters as females and 4.8 to 6.4 millimeters as males, the alpine volcano wolf is one of the smaller species of voles ( Arctosa ) whose physical structure it essentially corresponds to. A striking feature of the species, however, is its eye position, which is unusual for wolf spiders. The two eyes in the middle row are roughly behind the middle eyes in the front row. In other species of wolf spiders, these eyes are usually just behind the outer first-row eyes. The trapezoid formed by the four eyes of the back row of the Alpine Wühlwolf thus appears to be strongly extended backwards.

The prosoma (front body) is 3.8 to 4.1 millimeters long in the female and 3.6 to 3.8 millimeters in length in the male. The carapace (back shield of the prosoma) is reddish-brown in color and has darker stripes that extend from the fovea (apodem). Two of these stripes appear much darker and stronger and clearly mark the end between the head area, which is densely covered with grayish hair, and the rest of the prosoma. The legs are colored similar to the carapace, with the third and fourth pair of legs alternating with pale and dark ringlets.

The opisthosoma (abdomen) is also reddish to brown in color and shows a conspicuous white heart spot, which is bordered by black and rough lines at the back. Further back on the opisthosoma there are dark spots and on its flanks two to three circular black spots, from which fine, dark lines extend.

Structure of the sexual organs

The bulbi (male genital organs) of the Alpine Voles are characterized by a curvature that, viewed from the side, is reminiscent of the beak of a bird of prey .

Little information is available about the structure of the epigyne (female sex organ) of the species.

Similar Art

A species that is very similar to the Alpine volesus is the Arctosa renidescens , which belongs to the same genus and from which it can be most reliably distinguished by its genital morphological characteristics.

subspecies

In addition to the nominate form Arctosa alpigena alpigena , the subspecies Arctosa alpigena lamperti has been described, which is known as the raised bog wolf . But these subspecies has no different from the nominal form dense, a Skopula (hairiness of the foot members) resembling bristles to the tarsi and no dark spots on the femurs (thigh) on. However, due to the structure of the sexual organs, the alpine and high moor wolves cannot be clearly distinguished from one another.

Occurrence

The alpine volar wolf occurs in North America , in Greenland and in parts of Europe up to the Far Eastern part of Russia . In Europe, the species has been detected in northern and central Europe , the Alpine regions of France and Italy and in the United Kingdom , although its range here is limited to the mountains of Scotland . In Eastern Europe , occurrences of the alpine grinder have been described, apart from the western and northern European parts of Russia, including Kaliningrad, also from the Baltic states and Romania .

Habitats

Warm grassy areas above the tree line like this one in the Alps in East Tyrol are inhabited by Alpenwühlwolf.

The Alpenwühlwolf preferably inhabited warm grass surfaces including gritty grass and dwarf-shrub in mountains and can generally only from a height of between at least 800 meters and a maximum of about 3030 meters above sea level and above the tree-line are encountered.

In Europe, the main distribution area of ​​the species is in the Alps , with a focus on the Central Alps. At lower altitudes and outside the Alps, finds of the alpine grinder are much rarer. In Scandinavia , the raised bog wolf ( A. alpigena lamperti ) has also been identified as a subspecies of the Alpine wolf in bogs.

Threat and protection

As other bound to specific habitats Wühlwölfe ( Arctosa ), about bonded to sandy or gravelly riverside Arctosa cinerea ( Arctosa cinerea ) is also exposed to the Alpenwühlwolf a high hazard risk, which is reflected in its low inventories. The species is listed in the Red List of Endangered Species, Animals, Plants and Fungi in Germany in the R category ("extremely rare"). There is hardly any information about its population development. The raised bog wolf ( Arctosa alpigena lamperti ) is also endangered and is listed in category 2 ("endangered").

In the United Kingdom, too, due to its very limited distribution area, a threat to the population of the Alpine Voles is assumed and it is listed there by the IUCN in the VU ("vulnerable") category. The general population of the species is not assessed by the IUCN.

Way of life

Like most other voles ( Arctosa ), the Alpine Voleswolf creates living tubes lined with webs and leads a very hidden way of life. The spider hardly leaves its shelter and is very rarely found on the ground. The alpine voleswolf usually creates its living tube in the habitats it prefers in places with dense vegetation. He prefers those that are overgrown with crowberries ( Empetrum ) and blueberries ( Vaccinium ), bristle grass ( Nardus stricta ) as well as the lichen genus Cladonia and the deciduous moss genus Racomitrium .

Hunting behavior and catch of prey

Like most spiders, the Apenwühlwolf lives predatory and, like most of the wolf spider species, hunts without a safety net , but rather freely on the ground. The spider uses its well-developed sense of sight to locate prey. As soon as they come within range, they are jumped at and put out of action with a poisonous bite administered by the spider through its chelicerae (jaw claws) and then consumed.

The range of prey of the Alpine Voles includes other arthropods that do not exceed the hunter's own dimensions.

Life cycle

The life cycle of Alpenwühlwolfs divided as with most in the temperate climate zones common spider species in several phases depending on the seasons.

Phenology

The activity time for the adult female Alpine voles is from June to November. The males appear as early as May, but are rarely found in autumn.

Reproduction

The reproductive behavior of the Alpine Voles does not differ significantly from that of other wolf spiders. A sexually mature male seeks shelter for a female of its own species and performs a courtship dance that is common for wolf spiders . If the female signals readiness for mating, the male alternately introduces his bulbs into the epigyne of the female during mating.

Some time after mating, the female makes an egg cocoon , which, like other wolf spiders , it carries with it permanently attached to the spinnerets . After hatching, the young climb onto their mother's back and let them carry them for a while before they become independent. The younger spiders then grow up on their own and, after overwintering, reach sexual maturity in the following year.

Systematics

The alpine grinder was first described by Carl Ludwig Doleschall in 1852 , at which time it was incorporated into the genus Lycosa and thus received the name Lycosa alpigena . From Friedrich Dahl the way in 1908 for the first time in the genre of Wühlwölfe ( Arctosa provided) and thus mentioned in its still valid denomination. Due to the position of the eyes , the species was converted to the genus Tricca, which is now synonymous with the voles , and was therefore given the name Tricca alpigena . The same applied to the raised bog wolf ( A. a. Lamperti ), which at that time was recognized as an independent species and was given the name Tricca lamperti . Since the genus Tricca was synonymous in 1982 by Charles Denton Dondale and James H. Redner , the alpine voles are again in the genus of voles.

The species name alpigena comes from the Latin language and is a modified combination of the words Alpes (translated "Alps") and gigno (translated "born"), which means the species name translated means "born from the Alps".

The Alpine Voles have a total of two subspecies. These are:

  • Alpenwühlwolf (nominate form A. alpigena alpigena )
  • Hochmoorwühlwolf ( A. alpigena lamperti )

Individual evidence

  1. ↑ a b c d e f g h i Arctosa alpigena (Doleschall, 1852) from araneae - Spiders of Europe, accessed on June 29, 2020.
  2. ↑ a b c d e Heiko Bellmann: The cosmos spider leader. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, p. 190, ISBN 978-3-440-14895-2 .
  3. ↑ a b c L. Bee, G. Oxford, H. Smith: Britain's Spiders: A Field Guide , Princeton University Press, 2017, p. 232, ISBN 9780691165295 .
  4. ↑ a b c d e f g h Arctosa maculata (Hahn, 1822) at the Wiki der Arachnologische Gesellschaft e. V., accessed on June 19, 2020.
  5. ↑ Arctosa alpigena alpigena (Doleschall, 1852) at the Red List Center, accessed on June 29, 2020.
  6. ↑ Arctosa alpigena lamperti (Dahl, 1908) at the Red List Center, accessed on June 29, 2020.
  7. ↑ a b Arctosa alpigena (Doleschall, 1852) at the British Arachnological Society, accessed June 29, 2020.
  8. ^ Arctosa alpigena (Doleschall, 1852) from Global Biodiversity Information Facility , accessed on June 29, 2020.
  9. ↑ a b c d Arctosa alpigena (Doleschall, 1852) in the WSC World Spider Catalog , accessed June 29, 2020.

literature

  • Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, ISBN 978-3-440-14895-2 .
  • L. Bee, G. Oxford, H. Smith: Britain's Spiders: A Field Guide , Princeton University Press, 2017, ISBN 9780691165295 .

Web links

Commons : Alpenwühlwolf  - Collection of images, videos and audio files