Release of male courtship display in Periplaneta americana: evidence for female contact sex pheromone

Male American cockroaches (Periplaneta americana) are attracted to virgin females by volatile sex pheromones. After antennal contact with the female they turn through 180° and spread their wings in courtship display. A chemical contact stimulus releasing male courtship is demonstrated in the female cuticle. Experiments with standardized olfactory stimulation by volatile sex pheromones revealed that the contact stimulus is sex-specific and species-specific. It can be washed off the cuticle with non-polar solvents and was successfully transferred to glass dummies. However, it is not effective in the absence of volatile sex pheromones. Thus volatile sex pheromones are responsible for male attraction and sexual motivation, while mate recognition is accomplished through the contact pheromone.