Pheromones in Aphids: A Review

Abstract

Aphids release an alarm pheromone on being attacked by predators to signal other members of the colony to evacuate and to make sure they do not become preys to natural enemies. This pheromone induces the individuals to produce winged offsprings which can fly away from the plant to avoid predators. The most common constituent in the alarm pheromone was found to be (E) – β – Farnesene. It is also found that these pheromones released by the Aphids can be a trail for attracting natural enemies towards colonies and hence causing self harm. As this pheromone can cause harm to the aphids themselves, it is of a great advantage to plants which produce (E) – β – Farnesene as one of the volatiles suspected to be a naturally resistant against Aphid infestations. Plants releasing this volatile are found to be protecting their sap against these aphid infestations as these pests are able to perceive these volatiles and avoid sucking the sap and disperse to avoid being attacked by enemies.