Orb-weaver spider
Taxobox
name = Orb weaver spider
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superfamilia =
familia = Araneidae
familia_authority = Simon,
diversity_link = List of Araneidae species
diversity = 166 genera, c. 2,700 species
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subdivision_ranks = Genera
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"Argiope" (
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"Kaira"
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"Perilla"
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"many others"
The orb-weaver spiders (family "Araneidae") are the builders of spiral wheel-shaped webs often found in gardens, fields and forests. They have eight similar eyes, legs hairy or spiny and no stridulating organs. The family is cosmopolitan, including many well-known large or brightly colored garden spiders. There are more than 2800
Generally, orb-weaving spiders are three-clawed builders of flat webs with sticky spiral capture silk. The building of a web is an engineering feat, begun when the spider floats a line on the wind to another surface. The spider secures the line and then drops another line from the center, making a "Y". The rest of the scaffolding follows with many radii of non-sticky silk being constructed before a final spiral of sticky capture silk. The third claw is used to walk on the non-sticky part of the web. Characteristically, the prey
Some "orb-weavers" do not build webs at all. Members of the genera "Mastophora" in the Americas, "Cladomelea" in Africa and "Ordgarius" in
The spiny orb-weaving spiders in the genera "Gasteracantha" and "Micrathena" look like plant seeds or thorns hanging in their orb-webs. Some species of "Gasteracantha" have very long horn-like spines protruding from their abdomens.
One feature of the webs of some orb-weavers is the stabilimentum, a crisscross band of silk through the center of the web. It is found in a number of genera, but "Argiope", which includes the common garden spider of Europe as well as the yellow and banded garden spiders of North America, is a prime example. The band has been hypothesized to be a lure for prey, a marker to warn birds away from the web and a
Most arachnid webs are vertical and the spiders usually hang with their head downward. A few webs, such as those of orb-weaver in the genus "Metepiera" have the orb hidden within a tangled space of web. Some "Metepiera" are semi-social and live in communal webs. In Mexico such communal webs have been cut out of trees or bushes and used for living fly paper. Fact|date=August 2007
Natural history
The oldest known true orb-weaver is "
ystematics
The categorization into subfamilies and tribes follows Joel Hallan's [http://insects.tamu.edu/research/collection/hallan/Acari/Family/Araneidae.txt Biology Catalog] .
The
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Gallery
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Footnotes
reflist
References
*"The Life of the Spider" by John Crompton. Mentor,
*"The Orb-Weaving Spiders of Canada and Alaska. Araneae: Uloboridae, Tetragnathidae, Araneidae, Theridiosomatidae. Insects and Arachnids of Canada Series, Part 23." By C.D. Dondale, J.H. Redner, P. Paquin, and H.W. Levi. NRC Research Press, Ottawa,
*"How to Know the Spiders" by B. J. Kaston. Dubuque,
*"Spiders" by Barbara York Main. Sidney,
*"Biology of Spiders", by Rainer F. Foelix, second edition,
* (1993): The new orb-weaver genus "Lewisepeira" (Araneae: Araneidae). "Psyche" 100: 127-136. [http://psyche2.entclub.org/articles/100/100-127.pdf PDF]
* (2006): Oldest true orb-weaving spider (Araneae: Araneidae). "Biology Letters" 2: 447-450. doi|10.1098/rsbl.2006.0506 - [http://www.pubs.royalsoc.ac.uk/media/biology_letters/rsbl20060506.pdf PDF]
* (2008): [http://research.amnh.org/entomology/spiders/catalog/index.html The world spider catalog] , version 8.5. "American Museum of Natural History".
External links
* [http://www.xs4all.nl/~ednieuw/australian/Spidaus.html Spiders of Australia]
* [http://www.xs4all.nl/~ednieuw/Spiders/spidhome.htm Spiders of NW-Europe]
* [http://www.arachnology.org/Arachnology/Pages/Araneae.html Arachnology Home Pages: Araneae]
* [http://research.amnh.org/entomology/spiders/catalog/ World Spider Catalog]
* [http://www.uky.edu/Agriculture/CritterFiles/casefile/spiders/orbweavers/orb.htm University of Kentucky--Orb Weavers of Kentucky]
* [http://www.forestryimages.org/browse/subimages.cfm?SUB=13793 Pictures of "Mangora" species] (free for noncommercial use)
* [http://creatures.ifas.ufl.edu/beneficial/g_cancriformis.htm "Gasteracantha cancriformis", spinybacked orbweaver] on the
* [http://creatures.ifas.ufl.edu/misc/spiders/neoscona.htm "Neoscona crucifera" and "N. domiciliorum] on the