Contents of dufour glands of workers of three species of Tetramorium (Hymenoptera: Formicidae).

The Dufour glands of worker ants of Tetramorium caespitum, and the morphologically similar T. impurum are filled with similar, but species-specific mixtures of linear hydrocarbons and three homologous sesquiterpene corhpounds. Glands of workers ofT. caespitum contain, on average, 70 ng of oil containing C13 to C17 linear hydrocarbons with n-pentadecane (64%) and a mixture of pentadecenes (14%) as major components.T. impurum glands are smaller and contain an average of 40 ng of the same mixture but with n-pentadecane (49%) and a sesquiterpenoid compound (19%) the major components. Two isomeric pentadecenes, (Z)-6-pentadecene and (Z)-7-pentadecene are present in both species.T. semilaeve workers contain on average only 30 ng of a simple mixture of hydrocarbons with pentadecane contributing more than 90% of the total.