Volatile communication substances in Dufour's gland of virgin females and old queens of the antFormica polyctena

Dufour's gland, which is present in worker ants ofFormica polyctena as a tiny gland emptying into the short duct from the poison reservoir, was found to be very enlarged in virgin females. In egg-laying queens the gland lobes were reduced in size to slender tubes. The glandular secretion was analyzed by capillary gas chromatography and mass spectrometry. Seventy-four percent of the gland secretion from virgin females consisted of undecane, but this compound was less than 1% in queens. Decane and nonane, making up 3.5% in virgin females, were not found in queens. About 74% of their secretion consisted of the lower hydrocarbons: tridecane, pentadecane, heptadecane, and a nonadecene with tridecane dominating to 50%. Apart from these characteristic differences, almost the same compounds were present in virgin females and queens. Thirty-three compounds were identified from the secretion of virgin females and 38 from queens. An additional compound present in trace amounts in the secretion from queens has not been identified. All the compounds were hydro-carbons with the exception of dodecanol, present in trace amounts in virgin females. The compounds are homologous series of saturated, aliphatic hydrocarbons from nonane to tricosane and corresponding series of monounsaturated and methyl-branched hydrocarbons. Geranylgeraniol and geranyl-geranyl acetate, present in worker ants together with some other alcohols and acetates, were absent in females.