The preference for energetic resources is positively associated with predatory activity in ants

Abstract

1. Land use changes can alter resource availability and microclimate variables in tropical ecosystems, generally altering community structure by decreasing species richness and changing its composition. These changes affect foraging activity, nutrient preferences and consequently ecosystem functions. 2. Our aim was to assess how foraging activity and nutrient preference are influenced by changes in land use and microclimate. 3. We sampled ants (Formicidae) at 32 sites undergoing conversion from natural habitats to coffee systems in two Neotropical biomes: the Atlantic rainforest and the Cerrado. We assessed nutrient preference (amino acids, carbohydrates, lipids and sodium) and predation using mealworm larvae, while also measuring temperature and humidity. 4. We found the same ants foraged for different resources, likely because generalist species can perform these activities on the ground. Furthermore, foraging for energetic resources (carbohydrates and lipids) positively correlated with foraging for larvae. This indicates that the limitation of energetic resources can contribute to an increase in foraging and predatory activity. Moreover, ant preference for amino acids decreases with increasing temperature, indicating that ants prefer to consume energetic resources to support metabolic processes. 5. In conclusion, foraging is primarily carried out by generalist species. In addition, the preference for energetic nutrients, driven by energetic limitations, is linked to predatory activity. Moreover, ant species richness increases foraging for larvae, while rising temperatures decrease the preference for amino acids. Thus, conserving species richness and mitigating temperature increases may enhance larval foraging and support the insect predation function in Neotropical habitats.