I found a good site, with definition of ";heromone".
Definition: Pheromone = ectohormone - secreted outside the body into the
environment where they can have behavioural or physiological effects on other
animals (of the same species ???).

Some of the substances involved in plant defenses are thought to be aerosols from "saliva" of larvae or insects doing the chewing. Thiis would not fit pheromone definition.
A quote:"Dicke found that when spider mites attack lima bean plants, the plants release a chemical SOS that attracts another mite that preys on the spider mite."