Original Article

Testing the effect of a nest architectural feature in the fire ant Solenopsis invicta (Hymenoptera: Formicidae)

Tschinkel, W.R.

Abstract: When natural fire ant colonies (Solenopsis invicta) are sampled over five orders of magnitude of colony size, their production efficiency (new biomass per current biomass) remains constant, whereas in laboratory colonies, it declines. A striking difference between laboratory and natural nests is the subdivision of natural nests into hundreds of small chambers that limit the size of work groups. I tested the effect of nest subdivision on brood-rearing efficiency in lab oratory nests with a single chamber or many small chambers of equal total area. Nest subdivision had no significant effect on any measure of brood rearing efficiency or final colony size. Experiments are still needed to test cause-and effect relationships between specific features of ant nest architecture and specific colony functions. The results are discussed in the context of the superorganism.