Harvester ants are important weed seed predators in semi-arid cereal fields. Densities of
harvester ants vary considerably across fields and so do concomitant weed seed predation
rates, however, causes for variability are largely unknown. Understanding the factors that
affect ant density may help to identify areas where high natural weed seed control is likely
and management factors that could help to enhance ant densities where they are low.
Messor barbarus ant density was approximated by estimates of nest density and nest size …