Social-evolution
Guides
Anelosimus
cobweb spiders
Anelosimus is a genus of cobweb spiders (Theridiidae) renowned as a model system for studying the evolution of sociality in arachnids. The genus contains approximately 75 species exhibiting the full spectrum of social organization, from solitary to highly social (quasisocial). Eight quasisocial species have been documented, more than any other spider genus. Social species such as Anelosimus eximius form massive communal webs housing tens of thousands of individuals, while solitary species occur at higher altitudes and latitudes. The genus is cosmopolitan, with significant diversity in the Americas, Madagascar, and Australasia.
Bolitotherus
horned fungus beetle, forked fungus beetle
Bolitotherus is a genus of darkling beetles (Tenebrionidae) native to North America. The genus contains at least one well-documented species, Bolitotherus cornutus, commonly known as the forked fungus beetle or horned fungus beetle. All life stages are tightly associated with the fruiting bodies of wood-decaying bracket fungi, particularly species of Ganoderma and Fomes. These beetles have become important model organisms for studying sexual selection, social behavior, and population ecology in wild insect populations. Males possess distinctive thoracic horns used in combat for access to mating territories on fungal brackets.
Ceratina calcarata
Spurred Ceratina
Ceratina calcarata is a small carpenter bee native to eastern North America, ranging from Georgia to Ontario and east to Nova Scotia. It exhibits facultative subsocial behavior, with mothers providing extended care to offspring and producing a distinctive worker-like "dwarf eldest daughter" that forages for siblings. This species has become an important model organism for studying the evolutionary origins of social behavior, being the first subsocial bee species to have its genome published.
Halictinae
Sweat bees, Furrow bees
The Halictinae represent the largest and most diverse subfamily of Halictidae, comprising over 2,400 species across five tribes: Augochlorini, Thrinchostomini, Caenohalictini, Sphecodini, and Halictini. These small bees are characterized by extraordinary social diversity, ranging from solitary nesting to obligate eusociality, with eusociality having evolved approximately 20-22 million years ago. The subfamily serves as a key model system for studying social evolution due to its recent origins of eusociality and extensive behavioral polymorphisms within and between species.
Ponerinae
ponerine ants
Ponerinae is a diverse subfamily of ants containing approximately 1,600 species in 54 extant genera. Members are characterized by a single-segmented petiole and often a constricted gaster. The subfamily exhibits remarkable social flexibility, including multiple independent origins of gamergate reproduction where mated workers replace queens as functional egg-layers. Ponerines are primarily predatory and include some of the largest ants, such as Dinoponera gigantea. They serve as important model systems for studying the evolution of social behavior, foraging ecology, and morphological innovation.