Chemistry of metapleural gland secretions of three attine ants, Atta sexdens rubropilosa, Atta cephalotes, and Acromyrmex octospinosus (hymenoptera: formicidae)

The chemical composition of the secretions of the metapleural glands of workers and soldiers of two Atta species, Atta sexdens rubropilosa and A. cephalotes, and workers of Acromyrmex octospinosus, has been studied. As indicated by infrared spectrometry and confirmed by the ninhydrin test, the secretions contain chiefly proteins. Of the volatile acidic portion, which is present as ionized salts, phenylacetic acid is the major component in workers and soldiers of A. s. rubropilosa and A. cephalotes. Both Atta species also contain 3-hydroxydecanoic acid and its homolog as minor components together with indoleacetic acid. While there are qualitative similarities in the acidic composition in the secretions of A. s. rubropilosa and A. cephalotes, they differ quantitatively. The secretion of Acromyrmex octospinosus contains 3-hydroxydecanoic and indoleacetic acids, bur lacks phenylacetic acid. The bactericidal and fungicidal actions of the three major substances have been confirmed.