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Linepithema humile, invasive species, competition, resource depletion, foraging, Bernard Field Station


Linepithema humile, Argentine ants, alter their diets during times of resource depletion, favoring glucose-based foods over protein-based foods when food is scarce. We sought to determine the effect of competition on Argentine ant foraging preferences at the Robert J. Bernard Biological Field Station in Claremont, California. We hypothesized that Argentine ants with competition, colonies within a foot of another colony, would have a broader diet than Argentine ants with no competition. To analyze the foraging habits three food sources—Datura wrightii seeds, fruit flies, and cotton balls soaked in glucose—were provided to twelve ant colonies. Ant colonies with competition demonstrated a preference for glucose, while colonies without competition consumed similar quantities of glucose and fruit flies. Our results suggest that competition influenced diets as it caused Argentine ants to mainly consume glucose rather consuming a range of food.