Social-polymorphism
Guides
Anelosimus studiosus
tangle web spider, cobweb spider, social cobweb spider
Anelosimus studiosus is a subsocial tangle web spider in the family Theridiidae, distributed across much of North and South America from temperate to tropical regions. The species exhibits striking social polymorphism, with two distinct behavioral phenotypes: social spiders that live communally in large cooperative colonies, and asocial solitary individuals that defend individual territories. Social colonies involve multiple adult females sharing web maintenance, brood care, and cooperative prey capture without aggression. The frequency of the social phenotype increases at higher latitudes, correlating with colder temperatures where delayed juvenile development and maternal mortality risks favor communal living. Despite behavioral differences, the two phenotypes interbreed freely and produce viable offspring.
Formica neoclara
Bright Mound Ant
Formica neoclara is a socially polymorphic ant species distributed across western North America. The species exhibits alternative colony social structures—either single-queen (monogyne) or multiple-queen (polygyne)—controlled by a social supergene on chromosome 3. Polygyne colonies uniquely contain all three supergene genotypes, including workers homozygous for the monogyne-associated haplotype, a pattern not observed in other Formica species studied.
Pogonomyrmex californicus
California harvester ant
Pogonomyrmex californicus is a seed-harvesting ant native to southwestern North America. It is the most widely distributed species in the genus Pogonomyrmex. The species exhibits a striking social polymorphism: most populations have single-queen colonies (monogyny), but some California populations show primary polygyny where multiple unrelated queens cooperate in colony founding and coexist in mature colonies. It possesses a powerful sting and has been used historically by Indigenous peoples for ritual and medicinal purposes. The species is a prominent model for studying the evolution of social behavior, cooperation, and epigenetic regulation of aggression.