White widow
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White widow, female on a postage stamp from Kazakhstan . |
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| Latrodectus pallidus | ||||||||||||
| OP Cambridge , 1872 |
The white widow ( Latrodectus pallidus ), also known as the white steppe spider , is a spider belonging to the family of canopy web spiders (Theridiidae). It belongs to the genus of the real widows and was described by Octavius Pickard-Cambridge , a British arachnologist , in 1872 .
description
Characteristic of the white widow is its spherical abdomen and its long, thin legs. Unlike many species of the genus of true widows , which are grouped together as black widows because of the color of their abdomen , the white widow has a very light coloration instead of a dark color. The white widow is the only species in its genus that is so light in color, usually white or yellowish white. A drawing in the form of an hourglass as in the case of the black widows does not exist here either. The White Widow has four distinct point-like depressions on the otherwise smooth surface of the abdomen. These are almost in a rectangle, but the two front points are closer together than the two rear ones. While the abdomen is almost white in color, the front body and legs are variable. The cephalothorax (head and chest piece), like the legs, can either be brightly colored, but they are often yellowish-brown or have other shades of brown.
As with all species of true widows, the males are much smaller than the females.
Occurrence
The species occurs from North Africa across the Middle East and Iran to Russia and in several Central Asian countries such as Kazakhstan , Turkmenistan and Azerbaijan . From 1988, finds from the island of Sal from the archipelago of the Cape Verde Islands were also reported. In the distribution area, the white widow lives in steppes and desert-like landscapes.
Way of life
The species feeds on insects . To do this, it spins a complex hood net that consists of three parts: A hiding place on the side of the safety net with a living chamber and a tubular entrance is equipped with a 10 centimeter long and equally wide connection to the safety net. This hiding place, separated from the safety net, can fulfill several functions due to its tightly woven walls, which are often additionally reinforced by various remains of plants and prey. It protects the spider and later the eggs and newly hatched young from direct sunlight in the hot and dry areas where the white widow is found. Unlike most species of widow spiders, the nest is not built under stones or in holes in the ground, but on the low bushes that grow in these desert and steppe zones. Thanks to the system at a lofty height, convection currents can be used for cooling in addition to direct sun protection. However, this has the disadvantage that the building is easier to remove from optically oriented predators, e.g. B. birds, is to be discovered. By storing parts of plants and remains of prey in the cobweb, the shelter is additionally camouflaged and mechanically reinforced. Experiments in Israel with the northern gray shrike and nests of the widow spider Latrodectus revivensis , which also builds their nests in bushes, have shown that the more additional material reinforces the nest, the lower the risk of detection by the birds.
However, communication with the safety net via the bridge connection is also guaranteed during the day when the nocturnal spider is not directly observing the net. The safety net itself is smaller than that of other species of real widows, but it is more radial and flat than their hood nets. The construction of the entire network construction takes several days.
Research history
From a visit to what was then Palestine from mid-March to mid-May 1865, the British pastor and spider researcher Octavius Pickard-Cambridge brought 700 species of insects and 300 arachnids to London. Pickard-Cambridge gave an overview of 278 spider species that he had previously identified in the 1872 edition of the Proceedings of the Zoological Society of London . At that time more than half were still undescribed species and the work of Pickard-Cambridge included numerous first descriptions, including the white widow Latrodectus pallidus , which he had picked up from low bushes in the valley of the Jordan . Pickard-Cambridge immediately assigned the spider to the genus Latrodectus , from which it has never since been transferred to another genus. The specific epithet pallidus is the Latin word for "pale".
Bite accidents and toxicity
The species is not particularly aggressive and its bite is usually not dangerous to humans. But the bite of this spider can harm a person, even if the poison is not nearly as strong as in the southern black widow ( Latrodectus mactans ) native to North America or in the Australian red-backed spider ( Latrodectus hasselti ). However, the White Widow's bite can be fatal for the infirm or for children. Toxicological studies have shown that their poison is similar to that of the European black widow ( Latrodectus tredecimgutattus ).
Individual evidence
- ^ Norman I. Platnick: The World Spider Catalog, Version 10.5. American Museum of Natural History, 2000-2010 Family Theridiidae
- ^ Günter Schmidt : On the spider fauna of the desert island Sal (Republica do Cabo Verde) . In: M.-L. Célérier, J. Heurtault and C. (Eds.): Comptes rendus du XIIème Colloque européen d'Arachnologie. Bulletin de la Société européenne d'Arachnologie No. hors serie 1, pp. 310–313, Paris 1990 ISSN 0995-1067 full text ( Memento from October 6, 2014 in the Internet Archive ) (PDF, German; 150 kB).
- ↑ Avshalom Konigswald, Yael Lubin and David Ward: The effectiveness of the nest of a desert widow spider, Latrodectus revivensis, in predatory deterrence. Psyche, A Journal of Entomology, 97, pp. 75–80, 1990 full text (PDF, English; 704 kB)
- ↑ R. Szlep: The web-spinning process and web-structure of Latrodectus tredecimguttutus, L. pallidus and L. revivensis. Proceedings of the Zoological Society of London, 148, pp. 75-89, 1965
- ↑ AR Charakha, LV Shevchenko, AK Molodkin, KA Pluzhnikov, TM Volkova, EV Grishin: [Isolation and partial structural characteristics of major toxic components of Latrodectus pallidus venom]. In: Bioorganicheskaia khimiia. Volume 23, Number 3, March 1997, pp. 163-167, PMID 9190786 .
literature
- Octavius Pickard-Cambridge : General list of the spiders of Palestine and Syria, with descriptions of numerous new species, and characters of two new genera. Proceedings of the Zoological Society of London, pp. 212–354, 1872 (first description)
Web links
White widow in the World Spider Catalog