The secretion of the tegumental glands of the fifth and sixth gastral sternites ofP. dominulus and of its social parasiteP. sulcifer was analyzed by gas chromatography-mass spectrometry. Seven long-chain carboxylic acids have been identified: hexadecanoic, octadecadienoic and octadecenoic acids are the major components of the gland secretion ofP. dominulus and octadecenoic acid the main compounds ofP. sulcifer sternal gland secretion. The same carboxylic acids have been found on the nest pedicel.