All organisms need to regulate their intake of macro- and micronutrients in order to support energetic requirements and optimize the balance between growth, reproduction, and survival. Historically, ant nutrition studies have focused on protein and carbohydrate, showing forager’s ability to simultaneously regulate the intake of these two macronutrients. While the importance of dietary lipids on various physiological processes is now widely acknowledged in insects, studies on the intake regulation of this third macronutrient yielded mixed results. In this study, we used a combination of laboratory and field experiments to identify the mechanisms involved in the regulation of lipid intake in the red imported fire ant, Solenopsis invicta. We manipulated the composition of different lipids sources and recorded their attractiveness to ants in the lab and in the field to characterize the determinants of lipid intake regulation. Across our experiments, the consistency of the correlation between fatty acid composition and ant recruitment support our hypothesis that fatty acid profiles are the key drivers of lipid intake. However, our results also show that the proximate mechanisms for the regulation of lipid intake do not solely involve fatty acids and suggest several future research avenues for the determination of macronutrient intake regulation in ants.
