Abstract
Fertile queens of the antMonomorium pharaonis produce a chemical substance which is not present in worker ants or in young, alate (virgin) queens. The material has been identified as (E,E,E)-1-isopropenyl-4,8,12-trimethylcyclotetradeca-3,7,11-triene (neocembrene). This chemical is produced in the Dufour's gland of fertile queens and may serve as a queen-recognition pheromone.