It involves the use of natural enemies (parasites, predators) of the pest insects for their control and elimination. The use of microorganisms pathogenic to pests is also a method of biological (microbial) control.
Some of the examples of biological control of pests are as follows:
-
Ladybugs or praying mantis used in the control of aphids (pests).
-
Japanese beetle is controlled by bacteria causing milk spore disease in the larva of beetle.
-
Nuclear polyhedrosis virus is effective in eliminating the boll worms which damage cotton
-
Sex hormones (pheromones) released by female insect to attract their male counterparts are also used in pest control. They are specific for each species. Insect traps are set with specific pheromone hormones. The males are attracted in large numbers by the hormone and trapped. This checks the pest population
-
Frogs, spiders, toads, poultry birds are predators for several insects and there are purposely introduced to control the insect pests at proper time
