Lipid Food Preference and Transportation Using Tools by an Indian Ant Species Monomorium pharaonis (Hymenoptera: Formicidae): A Field Study

Abstract

Besides proteins and carbohydrates, the Pharaoh ant (Monomoroium pharaonis) prefers lipid foods especially when it becomes limiting in the colony. We used four different food-grade lipids such as mustard oil, sunflower oil, coconut oil and butter for seven consecutive days for a specified time frame (11.15 hr - 14.15 hr). There was a specific time zone in which the highest number of ants accumulated at all four food baits with varying peak values. Sunflower oil was the most preferred food, and mustard oil showed the lowest like. The differential number of ants in all four lipid food baits under observation can be attributed to the physical features and nutrient content. We also noted an interesting feature of the foraging activity: the major role of gathering and transporting food was performed primarily by two castes, intermediate and large, among the four distinct foraging castes. Most tools used in the present investigation were <0.5mm and of naturally available sand particles. They used the smallest tools more often as compared with the size of the other two categories. Our ant (M. pharaonis) transported only the butter-soaked smallest tools back to the nest. M. pharaonis used the smallest tools more often and this could be because the particular-sized tools were efficiently managed by the ant species under study. Our ants transported only the butter-soaked smallest tools back to the nest. It is revealed that butter was the most important lipid food for the particular ant colony of M. pharaonis.