Trilinolein identified as a sex-specific component of tergal glands in alates of Coptotermes formosanus

Hexane extracts of the tergal glands from female alates of the Formosan subterranean termite Coptotermes formosanus were analyzed by high performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry with collision-induced dissociation. Double bond configuration was determined by chemical modifications with gas chromatography-mass spectrometry. A single component, identified as the triacylglycerol, trilinolein, was unique to the female tergal glands. This compound was not found in other areas of the female alate abdomen or in the corresponding area of male alates. Neither gland extract nor trilinolein caused a behavioral response from male alates. However, significant differences were found between males and females for responses from neurons within sensilla of the maxillary palps.