Relationship Between Food Stores and Foraging Behavior of Pheidole ceres (Hymenoptera: Formicidae)

In temperate climates, animals that produce long-term food caches must forage simultaneously for nutrients to survive, reproduce, and collect enough stores to survive the winter. Thus, an animal is simultaneously makes two foraging choices 1) what nutrients to collect for its immediate needs and 2) what food items should be stored. The cues the animal uses to make these two decisions shoulddiffer.This studyexamined thenutrientcontentof a seed-cachingant,Pheidole ceres(Wheeler) (Hymenoptera: Formicidae), to determinewhether the nutrients found in stored seedswere different from the cues used to forage. The quantity of carbohydrates, lipids, amino acids, and proteins was measured in individual ants and seeds taken from eight P. ceres Þeld colonies once a month from April to October. The relative nutrient levels were compared with the known foraging preferences of P. ceres at different times of the year. Seeds serve as the primary lipid and protein storage vessels, whereas theworkers storeaminoacids andcarbohydrates.The levelsof carbohydrates andaminoacids matched the foraging preferences for carbohydrates and proteins, respectively. This pattern suggests that the ants use nutrients that are not abundant in seeds as forging cues.