Dunn, J.D., Hodapp, D., Menzel, F. &  Kohlmeier, P.

Larval chemical cues induce rapid changes in foraging preferences of ant workers (Hymenoptera: Formicidae)

In many animals that form cooperative social systems, such as ants, only a small number of individuals take over foraging duties. These specialized foragers not only have to fulfill their own nutritional needs but also the demands of non-foraging individuals residing in the nest. This raises the question of how foragers receive cues regarding nutritional requirements of their nestmates to adjust their foraging preferences. In ants, which like most insects primarily communicate chemically, larvae might convey their demands through the emission of odors. Using the acorn ant Temnothorax longispinosus, we first demonstrated that the presence of larvae increases protein foraging but not carbohydrate foraging. We exposed colonies lacking their own larvae to larval chemical extracts and found that larval odors rapidly increased protein foraging but did not alter carbohydrate foraging. Gas chromatography and mass spectrometry analyses revealed that larval extracts primarily consist of n-alkanes, with n-alkanes accounting for more than 90% of all larval CHCs. Carbohydrate and protein foraging appeared to be independent of each other, indicating separate regulatory mechanisms. Our study offers new insights into colony-homeostasis maintenance and emphasizes the vital role of larvae and larval chemical cues in regulating colony behavior.

Open access, licensed under CC BY 4.0. © 2024 The Author(s).

Division of labor, brood, chemical communication, larvae, cuticular hydrocarbons, behavioral decisions