Anelosimus
Anelosimus is a cosmopolitan genus of cobweb spiders, currently containing 74 species. Anelosimus is a key group in the study of sociality and its evolution in spiders. It contains species spanning the spectrum from solitary to highly social, 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
, this genus includes 75 species:Anelosimus agnar Agnarsson, 2006 – MalaysiaAnelosimus amelie Agnarsson, 2009 – Comoros, MayotteAnelosimus analyticus – United States, MexicoAnelosimus andasibe Agnarsson & Kuntner, 2005 – MadagascarAnelosimus arizona Agnarsson, 2006 – United States, MexicoAnelosimus ata Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus baeza Agnarsson, 2006 – Mexico to BrazilAnelosimus bali Agnarsson, 2012 – BaliAnelosimus biglebowski Agnarsson, 2006 – TanzaniaAnelosimus buffoni Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus chickeringi Levi, 1956 – Mexico to PeruAnelosimus chonganicus Zhu, 1998 – ChinaAnelosimus crassipes – China, Korea, JapanAnelosimus darwini Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus decaryi – Seychelles, Madagascar, Comoros, MayotteAnelosimus dialeucon – YemenAnelosimus dianiphus – Australia Anelosimus domingo Levi, 1963 – Colombia to Suriname and PeruAnelosimus dubiosus – BrazilAnelosimus dubius – TanzaniaAnelosimus dude Agnarsson, 2006 – TanzaniaAnelosimus eidur Agnarsson, 2012 – New GuineaAnelosimus elegans Agnarsson, 2006 – Mexico to PeruAnelosimus ethicus – BrazilAnelosimus exiguus Yoshida, 1986 – China, Japan, Ryukyu Is.Anelosimus eximius – Lesser Antilles, Panama to Argentina Anelosimus fraternus Bryant, 1948 – HispaniolaAnelosimus guacamayos Agnarsson, 2006 – EcuadorAnelosimus hookeri Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus huxleyi Agnarsson, Veve & Kuntner, 2015 – MadagascarAnelosimus inhandava Agnarsson, 2005 – Brazil, ArgentinaAnelosimus iwawakiensis Yoshida, 1986 – Korea, JapanAnelosimus jabaquara Levi, 1956 – BrazilAnelosimus jucundus – Mexico to ArgentinaAnelosimus kohi Yoshida, 1993 – Malaysia, SingaporeAnelosimus lamarcki Agnarsson & Goh, 2015 – MadagascarAnelosimus linda Agnarsson, 2006 – MalaysiaAnelosimus lorenzo Fowler & Levi, 1979 – Brazil, Paraguay, Uruguay, ArgentinaAnelosimus luckyi Agnarsson, 2012 – New GuineaAnelosimus may Agnarsson, 2005 – MadagascarAnelosimus membranaceus Zhang, Liu & Zhang, 2011 – China Anelosimus misiones Agnarsson, 2005 – ArgentinaAnelosimus monskenyensis Agnarsson, 2006 – KenyaAnelosimus moramora Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus nazariani Agnarsson & Kuntner, 2005 – MadagascarAnelosimus nelsoni Agnarsson, 2006 – South AfricaAnelosimus nigrescens – Guyana, BrazilAnelosimus octavius Agnarsson, 2006 – Mexico to Costa RicaAnelosimus oritoyacu Agnarsson, 2006 – Mexico to EcuadorAnelosimus pacificus Levi, 1956 – Mexico to Costa Rica, JamaicaAnelosimus pantanal Agnarsson, 2006 – BrazilAnelosimus placens – SeychellesAnelosimus pomio Agnarsson, 2012 – Papua New Guinea Anelosimus potmosbi Agnarsson, 2012 – New GuineaAnelosimus pratchetti Agnarsson, 2012 – Australia Anelosimus pulchellus – Europe, Caucasus, Iran, North AfricaAnelosimus puravida Agnarsson, 2006 – Guatemala to PanamaAnelosimus rabus Levi, 1963 – BrazilAnelosimus rupununi Levi, 1956 – Trinidad to BrazilAnelosimus sallee Agnarsson & Kuntner, 2005 – MadagascarAnelosimus salut Agnarsson & Kuntner, 2005 – MadagascarAnelosimus seximaculatus – China Anelosimus studiosus – USA to ArgentinaAnelosimus subcrassipes Zhang, Liu & Zhang, 2011 – China Anelosimus sulawesi Agnarsson, 2006 – Indonesia Anelosimus sumisolena Agnarsson, 2005 – BrazilAnelosimus taiwanicus Yoshida, 1986 – Taiwan, Indonesia Anelosimus terraincognita Agnarsson, 2012 – possibly AustralasiaAnelosimus tita Agnarsson, Kuntner & Jencik, 2015 – MadagascarAnelosimus torfi Agnarsson, 2015 – MadagascarAnelosimus tosus – Mexico to PeruAnelosimus vierae Agnarsson, 2012 – Uruguay, ArgentinaAnelosimus vittatus – Europe, Turkey, Caucasus, IranAnelosimus vondrona Agnarsson & Kuntner, 2005 – MadagascarAnelosimus wallacei Agnarsson, Veve & Kuntner, 2015 – Madagascar