The chemical basis of an ant-seed interaction was investigated for the ant Aphaenogaster rudis and the ant-dispersed violet Viola odorata. A laboratory behavioral bioassay was developed to chemically identify the attractant responsible for the interaction. The ant attractant, localized in the elaiosome, was classified as a lipid by both field and laboratory bioassays. Assays of partially purified lipid extracts revealed that the principal attractant may be a diglyceride. Gas-liquid chromatography analysis of the hydrolyzed diglyceride fraction revealed oleic acid as the major fatty acid present, suggesting that either 1,2- or 1,3-diolein may be the attractant. Structure-activity correlations for lipid standards demonstrated a clear preference for the diglyceride 1,2-diolein. The data also suggest that ricinoleic acid is not the lipid eliciting the ant response to Viola odorata, as had been previously suggested.
- Aphaenogaster rudis
- Viola odorata