Caste-dimorphism
Guides
Colobopsis
Gate-keeper Ants
Colobopsis is a genus of ants in the subfamily Formicinae, first described by Mayr in 1861 and containing approximately 95 species. The genus is distinguished by pronounced worker caste dimorphism, with major workers possessing phragmotic (truncate, plug-shaped) heads used to block nest entrances. Members of the Colobopsis cylindrica group exhibit autothysis, a defensive behavior where minor workers rupture their gaster to release sticky, irritant mandibular gland secretions. The genus nests primarily in plant material including wood, galls, and dead branches. Colobopsis was historically treated as a subgenus of Camponotus but was restored to full generic status following a 2015 phylogenomic study that identified it as sister to all remaining Camponotini.
Pheidole subarmata
Pheidole subarmata is a species of big-headed ant in the genus Pheidole, first described by Mayr in 1884. The species belongs to one of the most diverse ant genera globally, with over 1,000 described species in the New World alone. As with other Pheidole species, it exhibits a dimorphic worker caste system with minor workers and major workers (soldiers) distinguished by head size. The species has been documented across South America and the Caribbean.
Pheidole xerophila
Pheidole xerophila is a species of ant in the genus Pheidole, first described by Wheeler in 1908. As a member of this hyperdiverse genus, it exhibits worker caste dimorphism with distinct minor and major worker morphs. The specific epithet 'xerophila' suggests an association with dry or arid environments. The species is documented in the Catalogue of Life and GBIF as accepted, with observations recorded on iNaturalist.