Colorful sand grinder

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Colorful sand grinder
Colorful sand voles (Arctosa perita), female

Colorful sand voles ( Arctosa perita ), female

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Family : Wolf spiders (Lycosidae)
Genre : Voles ( Arctosa )
Type : Colorful sand grinder
Scientific name
Arctosa perita
( Latreille , 1799)

The colorful sand wolf ( Arctosa perita ), also called colorful sand wolf spider , dune or beach wolf spider , is a spider from the family of wolf spiders (Lycosidae). The species is represented in the western Palearctic and was also introduced in Canada and possibly also in other areas of North America .

features

male

Both sexes of the Bunter Sandwühlwolf reach a body length of six to nine millimeters, with the male usually remaining slightly smaller and the length of the prosoma (front body) in the female four millimeters or slightly less and in the male three to 3.9 millimeters. The species has quite a contrasting color scheme, which also serves as camouflage.

The carapace (back shield of the prosoma , front body) has a yellow-brownish to red-brown basic color and is narrowly built. It is also marked with several light spots, two of which are larger near the back eyes. Others form two bands along the center of the carapace and thus leave a broad median band in the basic color that is jagged at the back. The coloring of the legs corresponds to that of the spider's body, they are clearly curled.

The opisthosoma (abdomen) has a brown basic color and is provided with an arrow-shaped, yellow-colored, median spit-mark and two whitish, yellowish or reddish-colored spots flanking the pike-spot. Further back there are two or more pairs of spots of the same color.

Features of the genital organs

In the male of the Bunter Sandwühlwolf, as in all spiders on the pedipalps (transformed extratomas on the frontal side of the prosoma), the bulbi (male genital organs) have an apophysis , a chitinized induration along the globe, which has a strong tooth ventrally.

As with all spiders, the female of the species has the epigyne (female sexual organ) on the underside of the opisthosoma , the individual spermathec of which has a broad and strongly sclerotized (hardened) front edge.

Similar species

Female of the closely related leopard voles ( Arctosa leoaprdus )

The Colorful Sand Wühlwolf can be confused with the Leopard Wühlwolf ( A. leoaprdus ) belonging to the same genus , which, in contrast to the Colorful Sand Wühlwolf, can only be found on the banks of waters. The Leoaprden Wühlwolf is patterned similarly, but has a darker color than the Colorful Sand Wühlwolf.

Occurrence

Female still covered in places with young animals near the town of Malvern in the English county of Worcestershire .

The original distribution area of ​​the colorful sand chopper extends from Europe via North Africa , Turkey, the Caucasus to Iran. In addition, the species was introduced in the Canadian province of British Columbia and has established itself there in the southwestern part of this province. In addition, in 2007 a male of the variegated sand wolf was detected in Washington State in the United States . The species has been detected at heights of four to 396 meters above sea level.

habitat

Sandy areas with little vegetation such as this dune on the coast of the East Frisian island of Borkum form the habitats of the colorful sand wolf spider.

According to its common name, the Bunte Sandwühlwolf lives exclusively in open sand areas with little vegetation, which are accepted as habitats in coastal areas as well as in inland regions . These include sand dunes , heaths , sand pits , clearings as well as sandy roadsides and banks of water.

Threat and protection

The variegated Sandwühlwolf is common in some areas, but the decline in sand areas to which the species is bound poses a not inconsiderable threat. A moderate decline is still to be recorded, but the overall situation of the species' populations seems to be less drastic as initially assumed and so the Colorful Sandwühlwolf is now listed in the Red List of Endangered Species of Animals, Plants and Fungi in Germany in the pre-warning level ("V"), while before 2016 it was classified in Category 3 ("endangered").

In the UK, however, the IUCN classifies the species as "safe". The global population of the Bunter Sandwühlwolf was not counted.

Way of life

Well camouflaged female on the sand surface

Like the other voles ( Arctosa ) and a few other wolf spiders, the colorful sandwolf digs burrows in their habitat , where they are well camouflaged due to their coloring. These have a depth of 30 and a width of 0.4 to 0.5 centimeters. They are lined with a loose web on the inside . Above, the residential tube is spun up. On warm days, the spider can be found at the mouth of the tube and basks there. To do this, she puts her legs close to the body and turns the leg width towards the sun.

In the event of malfunctions, the Colorful Sand Wühlwolf jerks back into its tube and remains there for a while until it comes out again after a few minutes. In the event of repeated disturbance, he completely spins the residential tube. The mouth of the tube, which is covered with sand, closes the cave from the outside and it can no longer be found visually. Occasionally the species also leaves its hiding place and uses a security thread to be able to find its way back to it, which it does in a flash in the event of a malfunction.

Hunting behavior and range of prey

Like all spiders, the Colorful Sandwühlwolf lives predatory and, like most species of wolf spiders, does not create a spider web for catching purposes, but hunts prey freely on the ground as a stalker . The prey spectrum preferably includes insects that are on the sandy bottom and near the spider. As with all wolf spiders, the prey is visually perceived and then overwhelmed by a poison bite that occurs after the prey has jumped.

Life cycle

The life cycle of the Bunter Sandwühlwolf is divided into several sections and is also significantly influenced by the seasons.

Phenology

The activity time for the female of the Bunter Sandwühlwolf is between March and November and for the male between March and October. In the period in between, wintering begins, which takes place in the residential tube. The living tube is closed from above by sand particles and spider silk . Wintered and then fully grown specimens can be found until June.

Reproduction and growth of the young

Female whose opisthosoma is completely covered with young animals.

The reproductive behavior of the Bunter Sandwühlwolf corresponds to that of other wolf spiders and mating takes place in this species in spring. Before this, the male approaches the female with waving pedipalps during courtship . Some time after copulation, the female creates an egg cocoon and then carries it around with her, as is usual with wolf spiders, attached to the spinnerets. After hatching, the young spiders climb onto their mother's opisthosoma, where they feed on the yolk of their eggs until the first molt. Some time later, the young leave their mother and then grow independently over several moults. The way of life corresponds to that of the adult spiders. The young animals reach this stage from September.

Systematics

The Bunte Sandwühlwolf has been renamed and rearranged several times in its description history. First descriptor Pierre André Latreille classified the species in the first description in 1799, like all spiders back then, in the genus Aranea and named it A. perita . The current name Arctosa perita was first used by Carl Ludwig Koch in 1847 and was used more frequently from there and then developed from 1965 to the name of the species that was used throughout.

The species name perita comes from the Latin language and means "experienced".

gallery

  • Dorsal view of a female

  • Frontal view of a female

  • Lateral view of a female

  • Rear view of a female

Individual evidence

  1. ↑ a b c d e f g Arctosa perita (Latreille, 1799) from araneae Spiders of Europe, by Wolfgang Nentwig, Theo Blick, Robert Bosmans, Daniel Gloor, Ambros Hänggi & Christian Kropf, accessed on April 20, 2020.
  2. ↑ a b c d e f g Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, p. 186, ISBN 978-3-440-14895-2 .
  3. ↑ a b c d e Arctosa perita (Latreille, 1799) at dewolli.de, accessed on April 20, 2020.
  4. ↑ a b Arctosa perita (Latreille, 1799) at dewolli.de, accessed on April 20, 2020.
  5. ↑ CD Dondale, JH Speaker: The Wolf Spiders, Nurseryweb Spiders, and Lynx Spiders of Canada and Alaska: Araneae: Lycosidae, Pisauridae, and Oxyopidae , Research Branch, Agriculture Canada, 1990, pp. 296-297, ISBN 9780660136288 .
  6. ↑ Rod Crawford: Album of English Boom Field Trip , accessed April 20, 2020.
  7. ↑ a b Arctosa perita (Latreille, 1799) at the British Arachnological Society, accessed on 20 April 2020th
  8. ↑ Arctosa perita (Latreille, 1799) the Red List Center, accessed on 20 April 2020th
  9. ↑ Arctosa perita (Latreille, 1799) at Global Biodiversity Information Facility , accessed on 22 April 2020th
  10. ↑ a b c d e f Arctosa perita (Latreille, 1799) at Naturspektrum, accessed on April 22, 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 .
  • CD Dondale, JH Speaker: The Wolf Spiders, Nurseryweb Spiders, and Lynx Spiders of Canada and Alaska: Araneae: Lycosidae, Pisauridae, and Oxyopidae , Research Branch, Agriculture Canada, 1990, ISBN 9780660136288 .

Web links

Commons : Bunter Sandwühlwolf  - Album with pictures, videos and audio files