The tangle-web spiders, also known as cobweb spiders and comb-footed spiders (family Theridiidae) are a large group (over 2200 species in 98 genera ) of three-dimensional space-web-builders found throughout the world. Theridiid spiders are entelegyne (have a genital plate in the female) araneomorph ecribellate (use sticky capture silk instead of woolly silk) spiders that often build tangle space webs and have a comb of serrated bristles (setae) on the tarsus of the fourth leg.
The family includes some model organisms for research. For example, the genus Latrodectus, the medically important widow spiders. In addition to studies characterizing their venom and its clinical manifestation, widow spiders are broadly used in research on spider silk, and on sexual biology including sexual cannibalism.
Anelosimus spiders are another model organisms in the family, used for the study of sociality, its evolution, and its ecological and evolutionary causes and consequences. They are particularly important for such studies as the genus contains species varying from solitary to permanently social, and because sociality has evolved frequently within the genus allowing comparative studies across species. These spiders are also a promising model for the study of inbreeding as their mating system co-varies with sociality, and all permanently social species are highly inbred.
One species in Theridion, the Hawaiian T. grallator, is used as a model to understand the selective forces and the genetic basis of color polymorphism within species. Theridion grallator is known as the "happyface" spider, as certain morphs have a pattern uncannily resembling a smiley face or a grinning clown face on their yellow body.
The family also contains the well studied kleptoparasitic species of the subfamily Argyrodinae (including Argyrodes, Faiditus, and Neospintharus) which often have triangular bodies. These spiders live in the webs of larger spiders and pilfer small prey caught by their host's web, eat prey killed by the host spider, and may consume silk from the host web, as well as attack and eat the host itself.
The largest genus with over 600 species currently placed in it is Theridion, but it is not monophyletic. Another large, but most likely polyphyletic genus is Achaearanea, that includes the common house spider.
Many theridiids trap ants and other ground dwelling insects by means of elastic sticky silk trap lines leading to the soil surface. Despite their name, cobweb, or tangle-web, spiders have a huge range of web architectures.
Recent years have seen advances in the systematics
of cobweb spiders with phylogenies
reconstructed using both morphological
data. The following classification is built on these results (see also Joel Hallan's Biology Catalog
- * Argyrodes Simon, 1864
- * Neospintharus Exline, 1950
- * Ariamnes Thorell, 1869
- * Deelemanella Yoshida, 2003
- * Faiditus Keyserling, 1884
- * Rhomphaea L. Koch, 1872
- * Spheropistha Yaginuma, 1957
- * Anatea Berland, 1927
- * Audifia Keyserling, 1884
- * Dipoena Thorell, 1869
- * Dipoenata Wunderlich, 1988
- * Emertonella Bryant, 1945
- * Euryopis Menge, 1868
- * Eurypoena Wunderlich, 1992
- * Gmogala Keyserling, 1890
- * Guaraniella Baert, 1984
- * Hadrotarsus Thorell, 1881
- * Lasaeola Simon, 1881
- * Phycosoma O. P.-Cambridge, 1879
- * Yaginumena Yoshida, 2002
- * Yoroa Baert, 1984
- * Crustulina Menge, 1868
- * Latrodectus Walckenaer, 1805
- * Steatoda Sundevall, 1833
- * Asygyna Agnarsson, 2006
- * Carniella Thaler & Steinberger, 1988
- * Cerocida Simon, 1894
- * Craspedisia Simon, 1894
- * Enoplognatha Pavesi, 1880
- * Helvidia Thorell, 1890
- * Pholcomma Thorell, 1869
- * Phoroncidia Westwood, 1835
- * Proboscidula Miller, 1970
- * Robertus O. P.-Cambridge, 1879
- * Selkirkiella Berland, 1924
- * Styposis Simon, 1894
- * Theonoe Simon, 1881
- * Wirada Keyserling, 1886
- * Chrosiothes Simon, 1894
- * Episinus Walckenaer, in Latreille, 1809
- * Moneta O. P.-Cambridge, 1870
- * Spintharus Hentz, 1850
- * Thwaitesia O. P.-Cambridge, 1881
- * Stemmops O. P.-Cambridge, 1894
- * Achaearanea Strand, 1929
- * Achaearyopa Barrion & Litsinger, 1995
- * Ameridion Wunderlich, 1995
- * Cabello Levi, 1964
- * Cephalobares O. P.-Cambridge, 1870
- * Chrysso O. P.-Cambridge, 1882
- * Coleosoma O. P.-Cambridge, 1882
- * Cyllognatha L. Koch, 1872
- * Dipoenura Simon, 1908
- * Echinotheridion Levi, 1963
- * Exalbidion Wunderlich, 1995
- * Helvibis Keyserling, 1884
- * Histagonia Simon, 1895
- * Jamaitidion Wunderlich, 1995
- * Keijia Yoshida, 2001
- * Macaridion Wunderlich, 1992
- * Molione Thorell, 1892
- * Neottiura Menge, 1868
- * Nesticodes Archer, 1950
- * Nipponidion Yoshida, 2001
- * Paratheridula Levi, 1957
- * Propostira Simon, 1894
- * Rugathodes Archer, 1950
- * Sardinidion Wunderlich, 1995
- * Simitidion Wunderlich, 1992
- * Takayus Yoshida, 2001
- * Tekellina Levi, 1957
- * Theridion Walckenaer, 1805
- * Theridula Emerton, 1882
- * Thymoites Keyserling, 1884
- * Tidarren Chamberlin & Ivie, 1934
- * Wamba O. P.-Cambridge, 1896
- * Anelosimus Simon, 1891
- * Astodipoena Petrunkevitch, 1958 † (fossil, Eocene)
- * Chorizopella Lawrence, 1947
- * Clya Koch & Berendt, 1854 † (fossil, Eocene)
- * Coscinida Simon, 1895
- * Eodipoena Petrunkevitch, 1942 † (fossil, Eocene)
- * Eoysmena Petrunkevitch, 1942 † (fossil, Eocene)
- * Flegia Koch & Berendt, 1854 † (fossil, Eocene)
- * Hetschkia Keyserling, 1886
- * Icona Forster, 1955
- * Kochiura Archer, 1950
- * Landoppo Barrion & Litsinger, 1995
- * Marianana Georgescu, 1989
- * Mictodipoena Petrunkevitch, 1958 † (fossil, Eocene)
- * Municeps Petrunkevitch, 1942 † (fossil, Eocene)
- * Nactodipoena Petrunkevitch, 1942 † (fossil, Eocene)
- * Paidiscura Archer, 1950
- * Tomoxena Simon, 1895
- * Zercidium Benoit, 1977
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- Agnarsson I. 2006b. Asymmetric female genitalia and other remarkable morphology in a new genus of cobweb spiders (Theridiidae, Araneae) from Madagascar. Biological Journal of the Linnean Society 87: 211-232. PDF
- Agnarsson I. 2006c. Phylogenetic placement of Echinotheridion (Araneae: Theridiidae) - do male sexual organ removal, emasculation, and sexual cannibalism in Echinotheridion and Tidarren represent evolutionary replicas? Invertebrate Systematics 20: 415-429. PDF
- Agnarsson I. 2004. Morphological phylogeny of cobweb spiders and their relatives (Araneae, Araneoidea, Theridiidae). Zoological Journal of the Linnean Society 141: 447-626. PDF
- Cooperative behavior of Anelosimus jabaquara (2002). PDF
- Arnedo, M.A., Coddington, J., Agnarsson, I. & Gillespie, R.G. (2004). From a comb to a tree: phylogenetic relationships of the comb-footed spiders (Araneae, Theridiidae) inferred from nuclear and mitochondrial genes. Molecular Phylogenetics and Evolution 31:225-245. PDF
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- Grostal, P. and Walter, D.E. 1997. Kleptoparasites or commensals? Effects of Argyrodes antipodianus (Araneae: Theridiidae) on nephila plumipes (Araneae: Tetragnathidae). Oecologia, 111: 570-574.
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- Purcell, J. and Aviles, L. 2007. Smaller colonies and more solitary living mark higher elevation populations of a social spider. Journal of Animal Ecology, 76: 590-597.
- Vollrath, F. 1979. Behavior of the Kleptoparasitic Spider Argyrodes-Elevatus (Araneae, Theridiidae). Animal Behaviour, 27: 515-521.