Defensive and pheromonal secretion of the tergal gland of Aleochara curtula : I. The chemical composition.

The defensive secretion from the tergal gland of the staphylinid beetle,Aleochara curtula, acting as a supplementary mating stimulant, was investigated by gas-liquid chromatography, mass spectrometry, and IR spectroscopy. The reservoir contains a complex mixture of hydrocarbons, aliphatic aldehydes, and substituted 1,4-benzoquinones.n-Undecane, 1-undecene, and (Z)-4-tridecene were identified as the major hydrocarbon components. The main aldehydes aren-dodecanal and (Z)-5-tetradecenal, and the chief quinones are toluquinone and 2-methoxy-3-methyl-1,4-benzoquinone, the latter being established structurally by comparison of the mass spectra of the three synthesized isomers. Quantitative GLC analyses revealed no sex specificity of the relative concentrations of the compounds.