Three cuticular amides in the tripartite symbiosis of leafcutter ants

Cuticular hydrocarbons (CHCs) play various roles in insects' chemical ecology. As leafcutter ants live in a specific symbiosis with fungi, they harvest and with different bacteria, some of these CHCs might be associated with a mutualistic function within this symbiosis. To obtain a more precise picture in that respect we compared the CHC profiles of the leafcutter ants, Atta sexdens, Atta cephalotes, and Acromyrmex octospinosus inhabited by mutualistic bacteria with the profiles of Polyrhachis dives and Messor aciculatus by GC-EI-MS analysis and 28 other ant species by data from the literature. We were able to identify three alkyl amides (hexadecanamide, hexadecenamide, and tetradecanamide), occurring only in the CHC profiles of leafcutter ants inhabited by symbiotic bacteria. Our results lead to the conclusion that those alkyl amides could have a function in the tripartite symbiosis of leafcutter ants.

Automated summary

Cuticular hydrocarbons (CHCs) have various roles in insects' chemical ecology. Leafcutter ants have a specific symbiosis with fungi and different bacteria, and some of the CHCs may have mutualistic functions in this symbiosis. By comparing the CHC profiles of leafcutter ants with symbiotic bacteria to other ant species, researchers identified three alkyl amides that are specific to leafcutter ants with symbiotic bacteria. The results suggest that these alkyl amides may play a role in the tripartite symbiosis of leafcutter ants.