The correct answer is option 3, which states that the method not used as a biological control is the use of pesticides. Biological control is a method of controlling pests or diseases using other living organisms.
Option 1 suggests using predators of a pest as a method of biological control. This involves introducing natural enemies, such as predators or parasitoids, to control the population of a pest organism.
Option 2 mentions the use of pheromone traps. Pheromones are chemical signals produced by insects to communicate with each other. By using pheromone traps, the insects can be lured and caught, helping in the control of their population.
Option 4 mentions the use of neem extracts. Neem is a plant with insecticidal properties, and its extracts are used as a natural pesticide in biological control methods.
In conclusion, option 3, the use of pesticides, is not a method used in biological control as it involves the use of chemicals rather than living organisms.