Close-up of a fire ant; note the large head and mandibles

Recent Article: Sociometry of Solenopsis Geminata Reveals Variation in Colony-Level Phenotypes in Fire Ants

Abstract: In social insects, natural selection operates at the level of the colony, rather than the individual, but our understanding of how colony-level phenotypes arise and vary between species is lacking. Here, we test how colony-level phenotypes vary within the fire ants by measuring the composition of colonies of the tropical fire ant, Solenopsis geminata, over a wide range of sizes at multiple times throughout the year. Similar to the well-studied fire ant species S. invicta, we find that S. geminata colony composition varies strongly with colony size, such that as colonies grow they produce increasingly large workers as well as queens and males. However, major production increases more rapidly with colony size in S. geminata than in S. invicta,