Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes around 3,000 species in 128 genera, and is the most common arthropod group found in human dwellings throughout the world.
Theridiid spiders are both entelegyne, meaning that the females have a genital plate, and ecribellate, meaning that they spin sticky capture silk instead of woolly silk. They have a comb of serrated bristles (setae) on the tarsus of the fourth leg.
The family includes some model organisms for research, including the medically important widow spiders. They are important to studies characterizing their venom and its clinical manifestation, but widow spiders are also used in research on spider silk and sexual biology, including sexual cannibalism. Anelosimus are also model organisms, used for the study of sociality, because it has evolved frequently within the genus, allowing comparative studies across species, and because it contains species varying from solitary to permanently social. These spiders are also a promising model for the study of inbreeding because all permanently social species are highly inbred.
The Hawaiian Theridion grallator is used as a model to understand the selective forces and the genetic basis of color polymorphism within species. T. grallator is known as the "happyface" spider, as certain morphs have a pattern resembling a smiley face or a grinning clown face on their yellow body.
Webs They often build tangle space webs, hence the common name, but Theridiidae has a large diversity of spider web forms. Many trap ants and other ground dwelling insects using elastic, sticky silk trap lines leading to the soil surface. Webs remain in place for extended periods and are expanded and repaired, but no regular pattern of web replacement has been observed.
The well studied kleptoparasitic members of Argyrodinae (Argyrodes, Faiditus, and Neospintharus) live in the webs of larger spiders and pilfer small prey caught by their host's web. They eat prey killed by the host spider, consume silk from the host web, and sometimes attack and eat the host itself.
Theridiid gumfoot-webs consist of frame lines that anchor them to surroundings and of support threads, which possess viscid silk. These can either have a central retreat (Achaearanea-type) or a peripheral retreat (Latrodectus-type). Building gum-foot lines is a unique, stereotyped behaviour, and is likely homologous for Theridiidae and its sister family Nesticidae.
Among webs without gumfooted lines, some contain viscid silk (Theridion-type) and some that are sheet-like, which do not contain viscid silk (Coleosoma-type). However, there are many undescribed web forms.
Taxonomy The largest genus is Theridion with over 600 species, but it is not monophyletic. Parasteatoda, previously Achaearanea, is another large genus that includes the North American common house spider.
Genera
, this family includes 138 genera and 2,619 species:
Achaearanea Strand, 1929 – Gabon, Comoros, South Africa, Ivory Coast, China, Southeast Asia, India, Canary Islands, Puerto Rico, Costa Rica, Panama, Australia, South America Achaearyopa Barrion & Litsinger, 1995 – Philippines Achaeridion Wunderlich, 2008 – Turkey Allothymoites Ono, 2007 – China, Japan, Vietnam Ameridion Wunderlich, 1995 – North America, South America Anatea Berland, 1927 – Australia, New Caledonia Anatolidion Wunderlich, 2008 – Algeria, Morocco, Europe Anelosimus Simon, 1891 – Africa, Asia, Hispaniola, Jamaica, Mexico, United States, Australia, New Guinea, South America Anttheridion Jocqué & Vanuytven, 2025 – Democratic Republic of the Congo, Malaysia Argyrodella Saaristo, 2006 – Madagascar, Seychelles Argyrodes Simon, 1864 – Africa, Asia, Canary Islands, Jamaica, Hawaii, Mexico, United States, Oceania, French Guiana, Galapagos, Peru, Caribbean to Argentina, East Africa, Mediterranean to West Africa, Tongatabu. Introduced to Seychelles, South Africa, St. Helena, India, Hawaii, Madagascar? Ariamnes Thorell, 1869 – DR Congo, Equatorial Guinea, Gabon, South Africa, Guinea-Bissau, Asia, Cuba, Hispaniola, Costa Rica, Panama, Hawaii, Mexico, Australia, Papua New Guinea, New Zealand, Brazil, Peru Asagena Sundevall, 1833 – Algeria, Tunisia, Asia, Switzerland, Russia, Greece, Italy, Slovenia, France, North America Asiopisinus Hu, Wei, Liu & Xu, 2025 – Eastern Asia Asygyna Agnarsson, 2006 – Madagascar Audifia Keyserling, 1884 – Congo, Guinea-Bissau, Bolivia, Brazil Bardala Saaristo, 2006 – Seychelles Borneoridion Deeleman & Wunderlich, 2011 – Malaysia Brunepisinus Yoshida & Koh, 2011 – Borneo Cabello Levi, 1964 – Venezuela Cameronidion Wunderlich, 2011 – Malaysia Campanicola Yoshida, 2015 – Eastern Asia Canalidion Wunderlich, 2008 – Russia, Scandinavia Carniella Thaler & Steinberger, 1988 – Angola, China, Korea, Taiwan, Indonesia, Thailand, Nepal, Central Europe, Romania, Belgium Cephalobares O. Pickard-Cambridge, 1871 – China, India, Sri Lanka Cerocida Simon, 1894 – Brazil, Guyana, Venezuela Chikunia Yoshida, 2009 – Asia, Russia Chorizopella Lawrence, 1947 – South Africa Chrosiothes Simon, 1894 – Eastern Asia, Dominican Rep, Jamaica, St. Vincent, Mexico, United States, South America Chrysso O. Pickard-Cambridge, 1882 – Asia, Hungary, Russia, France, Trinidad, Costa Rica, Panama, North America, South America Coleosoma O. Pickard-Cambridge, 1882 – Cape Verde, Asia Coscinida Simon, 1895 – Angola, Congo, Tanzania, Asia, southern Europe Craspedisia Simon, 1894 – China, Hispaniola, Brazil Crustulina Menge, 1868 – Ethiopia, Madagascar, Tanzania, Algeria, Egypt, Morocco, Asia, Canary Islands, Ukraine, Russia, Jamaica, North America, Australia, New Caledonia, New Guinea, East Africa Cryptachaea Archer, 1946 – Asia, Russia, Trinidad, Costa Rica, Panama, North America, Australia, New Zealand, South America Cyllognatha L. Koch, 1872 – India, Australia, Samoa Deelemanella Yoshida, 2003 – Madagascar, Malaysia, Papua New Guinea Dipoena Thorell, 1869 – Africa, Asia, Europe, North America, Australia, Vanuatu, South America Dipoenata Wunderlich, 1988 – Madeira, Malta, Panama, Brazil, Venezuela Dipoenura Simon, 1909 – Sierra Leone, China, Indonesia, Laos, Vietnam, India Echinotheridion Levi, 1963 – Canary Islands, Madeira, South America Emertonella Bryant, 1945 – China, Mexico, United States. Introduced to China, Japan, India, Pakistan, Sri Lanka, New Guinea Enoplognatha Pavesi, 1880 – South Africa, Cape Verde, Asia, Europe, North America, Australia, Chile, Peru, North Africa. Introduced to St. Helena, Canada Episinus Walckenaer, 1809 – Africa, Asia, Europe, Panama, Mexico, United States, New Zealand, South America Euryopis Menge, 1868 – Africa, Asia, Europe, Jamaica, North America, Australia, New Caledonia, New Zealand, Argentina, Bolivia, Brazil Eurypoena Wunderlich, 1992 – Cape Verde, Canary Islands Exalbidion Wunderlich, 1995 – Guatemala, Panama, Mexico, Caribbean to Brazil Faiditus Keyserling, 1884 – North America, South America Famakytta Pett & Agnarsson, 2025 – Madagascar, Seychelles, Korea, India, New Guinea Glebych Eskov & Marusik, 2021 – Peru Gmogala Keyserling, 1890 – Australia, New Guinea Grancanaridion Wunderlich, 2011 – Canary Islands Guaraniella Baert, 1984 – Brazil, Paraguay Gushangzao Lin & Li, 2024 – China, Japan Gyro Lin & Li, 2024 – China Hadrotarsus Thorell, 1881 – Taiwan, Australia, New Guinea. Introduced to Belgium Helenidion Sherwood, Marusik, Fowler, Stevens & Joshua, 2024 – St. Helena Helvibis Keyserling, 1884 – Trinidad, Panama, Brazil, Chile, Peru Helvidia Thorell, 1890 – Indonesia Hentziectypus Archer, 1946 – North America, Bolivia, Brazil, Colombia Heterotheridion Wunderlich, 2008 – China, Caucasus, Iran, Turkey, Russia Hetschkia Keyserling, 1886 – Brazil Histagonia Simon, 1895 – Botswana, South Africa Icona Forster, 1955 – New Zealand Jamaitidion Wunderlich, 1995 – Jamaica Janula Strand, 1932 – Asia, North America, Australia, South America Keijiella Yoshida, 2016 – Eastern Asia, Laos Knoflachia Marusik & Eskov, 2024 – Russia Kochiura Archer, 1950 – Cape Verde, St. Helena, Western Asia, Canary Islands, Madeira, Brazil, Chile, North Africa, Juan Fernández Islands Landoppo Barrion & Litsinger, 1995 – Philippines Lasaeola Simon, 1881 – Asia, Azores, Canary Islands, Russia, Portugal, Spain, Panama, Mexico, United States, Peru, Venezuela Latrodectus Walckenaer, 1805 – Africa, Asia, Australia, Europe, North America, New Zealand, South America Lokitandroka Pett & Agnarsson, 2025 – Comoros, Madagascar Macaridion Wunderlich, 1992 – Canary Islands, Madeira Magnopholcomma Wunderlich, 2008 – Australia Megama Hu, Zhong, Liu & Li, 2026 – China, Japan Meotipa Simon, 1895 – Asia, Pacific Islands. Introduced to Americas, Tropical Africa Molione Thorell, 1893 – Asia Moneta O. Pickard-Cambridge, 1871 – Seychelles, Asia, Russia, Australia, New Caledonia, New Zealand Montanidion Wunderlich, 2011 – Malaysia Nanume Saaristo, 2006 – Seychelles Neopisinus Marques, Buckup & Rodrigues, 2011 – Cuba, Hispaniola, Panama, Mexico, Brazil, Peru Neospintharus Exline, 1950 – Madagascar, Seychelles, Asia, Cyprus, Greece, Panama, North America, South America Neottiura Menge, 1868 – Algeria, Asia, Europe Nesopholcomma Ono, 2010 – Japan Nesticodes Archer, 1950 – Central. Introduced to St. Helena, China, Japan, Indonesia, Sri Lanka, Macaronesia, New Zealand, North Africa, Pacific Islands Nihonhimea Yoshida, 2016 – Seychelles, Asia. Introduced to Pakistan, Australia, New Guinea Nipponidion Yoshida, 2001 – Japan Nojimaia Yoshida, 2009 – China, Japan Ohlertidion Wunderlich, 2008 – Russia, North America Okumaella Yoshida, 2009 – Japan, Korea Paidiscura Archer, 1950 – Cape Verde, China, Japan, Korea, Azerbaijan, Georgia, Turkey, Europe, North Africa to Middle East Parasteatoda Archer, 1946 – Tunisia, Asia, Russia, Australia, New Guinea, Solomon Islands Paratheridula Levi, 1957 – USA to Chile Pholcomma Thorell, 1869 – Japan, Caucasus, Iran, Turkey, Azores, North America, New Zealand, Niue, Samoa, Argentina, Brazil, North Africa Phoroncidia Westwood, 1835 – Africa, Asia, Europe, Cuba, Jamaica, North America, Australia, Fiji, New Caledonia, Papua New Guinea, New Zealand, Samoa, South America Phycosoma O. Pickard-Cambridge, 1880 – Africa, Madagascar, Seychelles, Asia, Russia, Jamaica, Panama, New Zealand, Galapagos. Introduced to Hawaii Phylloneta Archer, 1950 – Asia, Russia, Spain, United States, North Africa. Introduced to St. Helena Physcoa Thorell, 1895 – China Platnickina Koçak & Kemal, 2008 – Kenya, Cape Verde, Asia, Russia, North America Proboscidula Miller, 1970 – Angola, Rwanda Propostira Simon, 1894 – India, Sri Lanka Pycnoepisinus Wunderlich, 2008 – Kenya Rhinocosmetus Vanuytven, Jocqué & Deeleman-Reinhold, 2024 – Asia Rhinoliparus Vanuytven, Jocqué & Deeleman-Reinhold, 2024 – Southeast Asia, Australia, New Caledonia, Papua New Guinea Rhomphaea L. Koch, 1872 – Mozambique, Seychelles, Tanzania, South Africa, St. Helena, Asia, Europe, St. Vincent, New Zealand, French Polynesia, Samoa, Argentina, Brazil, Venezuela. Introduced to India Robertus O. Pickard-Cambridge, 1879 – Democratic Republic of the Congo, Asia, Europe, North America Ruborridion Wunderlich, 2011 – India, Spain Rugathodes Archer, 1950 – Kazakhstan, Japan, Iran, Azores, Canary Islands, Madeira, Russia, North America. Introduced to Britain Sardinidion Wunderlich, 1995 – Georgia, Turkey, North Africa Selkirkiella Berland, 1924 – Argentina, Chile, Falkland Islands Sesato Saaristo, 2006 – Seychelles Seycellesa Koçak & Kemal, 2008 – Seychelles Simitidion Wunderlich, 1992 – Tunisia, Kazakhstan, Western Asia, Canary Islands, Cyprus, Greece, Spain, North Africa. Introduced to Canada Spheropistha Yaginuma, 1957 – Eastern Asia, Australia