Dufour gland secretions of workers of the ants Myrmica sulcinodis and Myrmica lobicornis, and comparison with six other species of Myrmica

The investigation of the chemical composition of the secretions of the Dufour glands of Myrmica sulcinodis and M. lobicornis, as a part of an extended study on Myrmica ants, has shown that the Dufour gland of M. sulcinodis is filled with a mixture of hydrocarbons consisting of straight chain alkanes and alkenes with 15-19 carbon atoms as found in M. rubra, and a mixture of terpenoid hydrocarbons, namely (Z,E)-α-farnesene, homofarnesene, and bishomofarnesene as found in M. scabrinodis. In M. lobicornis, only (Z,E)-α-farnesene and its homologues, homofarnesene and bishomofarnesene are present. The complete absence of linear hydrocarbons in the latter species makes it similar to M. scabrinodis. In both species the very volatile portion of the Dufour gland secretion is composed of ethanal, propanone and methylpropanal as found in the other species of Myrmica, studied earlier.