The species Phoracantha recurva (Coleoptera: Cerambycidae) is a plague that, in its larval stage, mainly attacks eucalyptus plantations. In order to document a profile of the compounds secreted by P. recurva larvae and analyze their biological activity, we identified the components present in the methanol/chloroform extract by gas chromatography/mass spectrometry. 41 compounds were found, several of which have been identified in the host species. An olfactometer was used to analyze the olfactory responses of ants (Camponotus morosus) to the P. recurva larvae and different doses of their secretions. The results suggest that the larval secretion repels the ants. The 79results are discussed in view of the existing literature.