Sex Attractant Pheromone of the Japanese Slave-Making Ant, Polyergus samurai

The objective of our project was to identify the sex attractant pheromone of queens of the slave-making ant Polyergus samurai, which was characterized as a blend of methyl 6-methylsalicylate and methyl 3-ethyl-4-methylpentanoate. Both compounds were identified in volatiles collected from squashed heads of queens, and in field trials, a blend of the two compounds was highly attractive to males. In contrast, males were not attracted to a blend of methyl 6-methylsalicylate with 3-ethyl-4-methylpentanol. Thus, the pheromone blend of this species is analogous to that of species in the Polyergus lucidus complex from eastern North America, rather than that of the Polyergus breviceps complex from western North America and the European species P. rufescens. These results are discussed in the context of speciation within the genus.