Similar window spider

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Similar window spider
Similar window spider (Amaurobius similis), female

Similar window spider ( Amaurobius similis ), female

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Family : Dark spiders (Amaurobiidae)
Genre : Amaurobius
Type : Similar window spider
Scientific name
Amaurobius similis
( Blackwall , 1861)

The similar window spider or house dark spider ( Amaurobius similis ) is a web spider from the family of the dark spiders (Amaurobiidae). The term similar window spider comes from the fact that it is very similar to the closely related and better known window spider ( Amaurobius fenestralis ). This is also expressed in the scientific species name similis , which in German means something like "similar" or "same". The second common name, house dark spider, indicates both belonging to the family of dark spiders and the synanthropy of the species that often brings them close to human dwellings.

features

male

The female of the similar window spider reaches a body length of nine to twelve, the male one of six to eight millimeters. Both sexes have a brown basic color. The prosoma is light to very dark red-brown in color, which becomes lighter from front to back. Specimens whose prosoma are lighter in color have visible radial stripes here. The sternum and carapace have the same color as the prosoma and the chelicerae are also red-brown in color. The opisthosoma is brown to dark brown in both sexes, although in the male the basic color and the color pattern are a little darker overall. On the anterior dorsal side of the opisthosoma there is a dark longitudinal spot that extends almost to the middle. This is surrounded by a yellow-brown markings that are wider at the back and protrude beyond the middle of the opitshosoma. It is not uncommon for a more or less distinct brown to dark brown angular drawing to follow directly behind. In addition, sometimes white hairs form another smaller one behind the first angle drawing. The legs of the similar window spider are red-brown, although the color can also be lighter. In addition, the legs have darker and indistinct ringlets and a large number of hairs. Like all dark spiders, the similar window spider also has a cribellum .

Similar species

Female of the window spider ( Amaurobius fenestralis ), with which the similar window spider is closely related.

Particularly noteworthy is the strong similarity to the aforementioned window spider. The similar window spider differs from this, among other things, by the dark spot, which is not lightened in the middle of the sister species, and also by the body length, which can be larger in the similar window spider. However, only genital morphological features of both species provide a reliable way of distinguishing them.

Occurrence

The similar window spider is naturally common in Europe and the Caucasus , while it was introduced in North America . The main distribution center of the species is, however, in western and northwestern Europe. There the species inhabits various forests and shrub landscapes as well as ruderal areas , parks , gardens and quarries . In the wild, it can be found especially under stones, dead wood, bark or on crevices of any kind. As the window spider or also to the genus Amaurobius counting cellar spider ( Amaurobius ferox can) The similar additional window spider in the areas of human habitation and thus as partially synanthropisch living species in basements, walls or to be found on windows.

Threat and protection

The similar window spider can be found differently depending on the area. In Western Europe, for example, it is often represented, while it appears to be completely absent in the East. Compared to the window spider or the cellar spider, the species is rarely found. The IUCN does not assess their endangerment.

Way of life

Females in his net, including a landluse .

Like all dark spiders, the Similar Window Spiders create a spider web for the capture of prey, consisting of a flat and irregularly structured web of cribellate and bluish-looking catching threads for the actual prey capture and an adjoining living tube that serves as the spider's abode. As soon as a suitable prey falls on or passes through the safety net, the spider jumps out, injects poison into the prey with a bite and then drags it back into the living tube to be consumed there. The principle of catching prey is therefore similar to that of other spiders that build trichomes, including that of the funnel spiders (Agelenidae). Other arthropods , preferably insects , woodlice or other spiders , fall into the prey pattern of the similar window spiders. The nocturnal species usually stays in the tube during the day. At night she can also be found on the net cover or near her safety net.

Reproduction

The mating season of the similar window spider is in spring. After mating, the female prepares to lay her eggs in summer by spinning the living tube of her web. Then it makes a relatively loose egg cocoon and provides it with 40 eggs. The cocoon is guarded by the female until the young spiders hatch, which eat their mother after hatching and then leave the brood chamber. One speaks of matriphage when eating the mother . The young then reach sexual maturity in the autumn of the second year of development before they can mate in the following spring. Adult specimens of both sexes can be found all year round, with the majority of the activity time of both sexes being limited to autumn and, in the case of females, to spring. The maximum lifespan of the similar window spider is two years.

Bite accidents and toxicity

The similar window spider is able to bite humans. However, bite accidents of the less aggressive kind only occur on the part of them in great distress, for example when the spider is squeezed. The bite itself usually proceeds without any health-relevant symptoms. In the area of ​​the bite wound there is a swelling that lasts for twelve hours, which can be quite painful compared to the effect of the actual bite. In one case, a bite victim who was bitten on the arm was noted to have numbness that subsided after an hour.

Systematics

First described by John Blackwall in 1861 as Ciniflo similis , the similar window spider received the name Amaurobius similis, which is still valid today, as early as 1868 from Carl Ludwig Koch . Subsequently, the type was given synonyms by different authors, especially according to gender. Two other names for the species were Callobius alaskanus (1947) by Ralph Vary Chamberlin and the first name Ciniflo similis (1951) by George Hazelwood Locket and Alfred Frank Millidge, which was used again . Hermann Wiehle ran the similar window spider again in 1953 as Amaurobius similis . Since then, this name has been used consistently for the species.

gallery

  • Top view of a female

  • Frontal view of a female

  • Rear view of a female

  • Frontal view of a male

  • Detail of a male

Individual evidence

  1. ↑ a b c d e f g h i j k l m n o Description of the similar window spider on the website of www.natur-in-nrw.de ( Link )
  2. ↑ a b Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, p. 182, ISBN 978-3-440-14895-2 .
  3. ↑ a b Amaurobius similis (Blackwall, 1861) in the WSC World Spider Catalog , accessed December 9, 2019.
  4. ↑ a b c d e f g h i Amaurobius similis (Blackwall, 1861) at araneae Spiders of Europe, by Wolfgang Nentwig, Theo Blick, Robert Bosmans, Daniel Gloor, Ambros Hänggi & Christian Kropf.
  5. ↑ Amaurobius similis (Blackwall, 1861) from Global Biodiversity Information Facility , accessed December 9, 2019.
  6. ↑ a b c Description of the similar window spider and its bite effect on the website of False Widow Spider ( Link )

literature

  • Heiko Bellmann: The cosmos spider guide. Over 400 species in Europe. Kosmos Naturführer, Kosmos (Franckh-Kosmos), 2nd edition, 2016, p. 182, ISBN 978-3-440-14895-2 .

Web links

Commons : Similar window spider  - collection of images, videos and audio files