Contents of poison apparatus and their relation to trail-following in the antDaceton armigerum.

The poison gland, which is the source of the trail pheromone inDaceton armigerum, contains a mixture of dimethylpyrazine, trimethylpyrazine and 3-ethyl-2,5-dimethylpyrazine in approximately equal proportions, similar to that of the antManica rubida. The cross-activity in trail-following tests with several other species can thus be explained. The Dufour gland ofD. armigerum contains a mixture of 26 identified hydrocarbons, chiefly 9-tricosene, tricosane, and 9-pentacosene. It also contains very small amounts of two sesquiterpene aldehydes, tetramorine-2 and tetramorine-3, already known in other myrmicine Dufour glands. No volatile substances were detected in the pygidial gland.