What are pheromones

After the discovery of the first insect sex attractant bombykol [(10 , 12Z)-10,12-hexadecadien-l-ol] by Butenandt and coworkers,1 the term pheromone was defined by Karlson and Llischer in 1959.2 The term was derived from the Greek pherein (carry or transfer) and horman (stir up or excite). Pheromones are substances that are secreted to the outside by an individual and received by a second individual of the same species, in which they release a specific reaction, for example, a definite behavior or a developmental process. 

Pheromones are classified into two categories, releaser pheromones and primer pheromones. Releaser (or signaller) pheromones cause changes of behaviors in the receivers, while primer pheromones cause physiological impacts on the receivers. Releaser pheromones can be further classified as sex pheromones, aggregation pheromones, trail pheromones, etc., according to the type of behavioral change. 

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