Biological control is a form of manipulating nature to achieve a desired effect. Biological control methods can be used as part of a broad-based program to reduce the environmental, legal, and health hazards of chemicals in the garden. In addition, biological control may be a less expensive alternative to certain insecticides. Some biological control measures can actually prevent economic damage to plants. Unlike most insecticides, biological controls are often very specific against a particular pest.
Biological control takes a little more management and planning.
It can take patience and record keeping. Successful use of biological control requires knowing the biology of the pest and its enemies. Many natural enemies are also susceptible to pesticides, so using them successfully requires care. In some cases, biological control may be more costly than pesticides, but the long-term advantages often outweigh the cost. Most natural enemies attack only one type of insect, but this can also be an advantage.