Anelosimus Darwini

''Anelosimus'' is a cosmopolitan genus of cobweb spiders (Theridiidae), currently containing 74 species. ''Anelosimus'' is a key group in the study of sociality and its evolution in spiders (Aviles 1997). It contains species spanning the spectrum from solitary to highly social (quasisocial), with eight quasisocial species, far more than any other spider genus. Among these is the South American social species '' Anelosimus eximius'', among the best studied social spider species.

The web of a colony of ''A. eximius'' can reach cover entire tree canopies and contain tens of thousands of individuals. Most of the highly social species live in lowland tropical forests, and all occur in the Americas. Other species, particularly those at higher altitudes in northern latitudes in the Americas and all non-American species appear to be solitary or sub-social. Social ''Anelosimus'' species are generally highly inbred and have female-biased sex ratios, with up to 10 females per male.

The social, subsocial, and solitary behavior of differing species within ''Anelosimus'' has been used to examine hypotheses of environmental pressures on social behavior, and inbreeding. Subsociality as a trait seems to be conserved, despite the wide range of environments in which ''Anelosimus'' species live; all known solitary species within the genus belong to a single clade. Sociality, however, has independently arisen several times.

Description

''Anelosimus'' spiders have a notched red or brown band on their abdomen, which is dark when preserved in alcohol. Laterally, the abdomen has a white band and/or white blotches. Specimens range in size from . Individuals in this genus lack a colulus.

Species

, the World Spider Catalog accepted the following species:

*''Anelosimus agnar'' Agnarsson, 2006 – Malaysia
*''Anelosimus amelie'' Agnarsson, 2009 – Comoro Is.
*'' Anelosimus analyticus'' (Chamberlin, 1924) – USA, Mexico
*''Anelosimus andasibe'' Agnarsson & Kuntner, 2005 – Madagascar
*''Anelosimus arizona'' Agnarsson, 2006 – USA, Mexico
*''Anelosimus ata'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*''Anelosimus baeza'' Agnarsson, 2006 – Mexico to Brazil
*'' Anelosimus bali'' Agnarsson, 2012 – Bali
*'' Anelosimus biglebowski'' Agnarsson, 2006 – Tanzania
*''Anelosimus buffoni'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*''Anelosimus chickeringi'' Levi, 1956 – Mexico to Peru
*''Anelosimus chonganicus'' Zhu, 1998 – China
*''Anelosimus crassipes'' (Bösenberg & Strand, 1906) – China, Korea, Japan, Ryukyu Is.
*'' Anelosimus darwini'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*''Anelosimus decaryi'' (Fage, 1930) – Aldabra, Madagascar, Comoro Is.
*''Anelosimus dialeucon'' (Simon, 1890) – Aden
*''Anelosimus domingo'' Levi, 1963 – Colombia to Suriname and Peru
*''Anelosimus dubiosus'' (Keyserling, 1891) – Brazil
*''Anelosimus dubius'' (Tullgren, 1910) – Tanzania
*''Anelosimus dude'' Agnarsson, 2006 – Tanzania
*''Anelosimus eidur'' Agnarsson, 2012 – New Guinea
*''Anelosimus elegans'' Agnarsson, 2006 – Mexico to Peru
*''Anelosimus ethicus'' (Keyserling, 1884) – Brazil
*''Anelosimus exiguus'' Yoshida, 1986 – China, Japan, Ryukyu Is.
*'' Anelosimus eximius'' (Keyserling, 1884) (type species) – Lesser Antilles, Panama to Argentina
*'' Anelosimus fraternus'' Bryant, 1948 – Hispaniola
*'' Anelosimus guacamayos'' Agnarsson, 2006 – Ecuador
*'' Anelosimus hookeri'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*'' Anelosimus huxleyi'' Agnarsson, Veve & Kuntner, 2015 – Madagascar
*'' Anelosimus inhandava'' Agnarsson, 2005 – Brazil, Argentina
*''Anelosimus iwawakiensis'' Yoshida, 1986 – Korea, Japan
*'' Anelosimus jabaquara'' Levi, 1956 – Brazil
*''Anelosimus jucundus'' (O. Pickard-Cambridge, 1896) – Mexico to Argentina
*'' Anelosimus kohi'' Yoshida, 1993 – Malaysia, Singapore
*'' Anelosimus lamarcki'' Agnarsson & Goh, 2015 – Madagascar
*'' Anelosimus linda'' Agnarsson, 2006 – Malaysia
*'' Anelosimus lorenzo'' Fowler & Levi, 1979 – Brazil, Paraguay, Uruguay, Argentina
*'' Anelosimus luckyi'' Agnarsson, 2012 – New Guinea
*'' Anelosimus may'' Agnarsson, 2005 – Madagascar
*'' Anelosimus membranaceus'' Zhang, Liu & Zhang, 2011 – China
*'' Anelosimus misiones'' Agnarsson, 2005 – Argentina
*'' Anelosimus monskenyensis'' Agnarsson, 2006 – Kenya
*'' Anelosimus moramora'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*'' Anelosimus nazariani'' Agnarsson & Kuntner, 2005 – Madagascar
*'' Anelosimus nelsoni'' Agnarsson, 2006 – South Africa
*'' Anelosimus nigrescens'' (Keyserling, 1884) – Guyana, Brazil
*'' Anelosimus octavius'' Agnarsson, 2006 – Mexico to Costa Rica
*'' Anelosimus oritoyacu'' Agnarsson, 2006 – Mexico to Ecuador
*'' Anelosimus pacificus'' Levi, 1956 – Mexico to Costa Rica, Jamaica
*'' Anelosimus pantanal'' Agnarsson, 2006 – Brazil
*'' Anelosimus placens'' (Blackwall, 1877) – Seychelles
*'' Anelosimus pomio'' Agnarsson, 2012 – New Britain
*'' Anelosimus potmosbi'' Agnarsson, 2012 – New Guinea
*'' Anelosimus pratchetti'' Agnarsson, 2012 – New South Wales
*'' Anelosimus pulchellus'' (Walckenaer, 1802) – Europe to Russia, Iran, North Africa
*'' Anelosimus puravida'' Agnarsson, 2006 – Guatemala to Panama
*''Anelosimus rabus'' Levi, 1963 – Brazil
*'' Anelosimus rupununi'' Levi, 1956 – Trinidad to Brazil
*'' Anelosimus sallee'' Agnarsson & Kuntner, 2005 – Madagascar
*'' Anelosimus salut'' Agnarsson & Kuntner, 2005 – Madagascar
*'' Anelosimus seximaculatus'' (Zhu, 1998) – China
*'' Anelosimus studiosus'' (Hentz, 1850) – USA to Argentina
*'' Anelosimus subcrassipes'' Zhang, Liu & Zhang, 2011 – China
*'' Anelosimus sulawesi'' Agnarsson, 2006 – Sulawesi
*'' Anelosimus sumisolena'' Agnarsson, 2005 – Brazil
*'' Anelosimus taiwanicus'' Yoshida, 1986 – Taiwan, Krakatau
*'' Anelosimus terraincognita'' Agnarsson, 2012 – possibly Australasia
*'' Anelosimus tita'' Agnarsson, Kuntner & Jencik, 2015 – Madagascar
*'' Anelosimus torfi'' Agnarsson, 2015 – Madagascar
*'' Anelosimus tosus'' (Chamberlin, 1916) – Mexico to Peru
*''Anelosimus vierae'' Agnarsson, 2012 – Uruguay
*'' Anelosimus vittatus'' (C. L. Koch, 1836) – Palearctic
*'' Anelosimus vondrona'' Agnarsson & Kuntner, 2005 – Madagascar
*'' Anelosimus wallacei'' Agnarsson, Veve & Kuntner, 2015 – Madagascar

References

{{Taxonbar, from=Q2446287

Theridiidae
Araneomorphae genera
Cosmopolitan spiders