The courtship-inhibiting pheromone is ignored by female-deprived gregarious desert locust males

Gregarious mature males of the desert locust (Schistocerca gregaria) emit a courtship-inhibiting pheromone continuously to repel rivals. This signal evokes a strong response from males with recent experience of mature females. However, if males have been female deprived for some time, they start to ignore the pheromone and attempt to usurp females that are guarded by males. The probability and intensity with which males struggle for an occupied mate was found to depend on the time previously spent without a female. This adaptive behaviour is similar to the response to host-marking pheromones in phytophagous insects and parasitoids.