Abdominal gland secretions of the samsum ant, Pachycondyla sennaarensis (Hymenoptera: Formicidae)

The genus Pachycondyla Smith 1858, with 200 described species, form a large group of ants in the subfamily Ponerinae. Most Pachycondyla species appear to be generalist scavengers or predators who subdue their prey with their venom. Samsum ants and their stinging behaviour are so far reported from Iran, Saudi Arabia and UAE and seem to be distributed throughout the Persian Gulf area, where their stinging behaviour has become a new source of health concern. Samsum ants are also depended on chemical communication for a variety of functions. These functions correspond to the huge variety of exocrine glands which are species-specific in chemical nature. The Dufour gland secretion of P. sennaarensis is a mixture of minute amounts of terpenoids (mainly 2,6,10-trimethylundecan-2,9-dien-4-one and a C20H38 diterpene), the methyl ketone pentadecan-2-one, and a complex mixture of linear and methyl-branched hydrocarbons. Ascending concentrations of heptadecane and nonadecane along with small titers of heptacosane and 2,6,10,14-tetramethyl hexadecane were also found. Venom gland secretions were consisted of Phenol-2,4-Bis (1,1 dimethylethyl), dibutyl phthalate and trimethyl pyrazine, as the main components. This work provides the first record of 2-alkanones in Dufour gland of ponerine ants and phenol-2,4-Bis (1,1 dimethylethyl) among insects.