(d) : Pheromones are volatile chemicals produced by a given species to communicate with other individuals of the same species to change their behaviour. The synthetic versions of lepidopteran pheromones can be used as pesticides. Sometimes the relative amount of several pheromone chemicals in a pesticide product determine which specific pests are controlled when the pesticide product releases pheromone into the air where males are looking for females, the males become confused and cannot easily locate the females. As a result, many of the females do not mate and lay eggs and there are many fewer offspring than usual. These insect pheromones are third generation pesticides. Other third generation pesticides are insect growth regulators, chitin synthesis inhibitors and juvenile hormones.