**3.5 Biological control**

Biological control/biocontrol involves the use of living organisms to manage cropdamaging pests. It is one of the oldest nonchemical control methods used in agriculture [48], and is probably the most well-researched part of the IPM concept. In biological control, arthropod pests are mainly controlled using biological control agent's viz. predators, parasitoids, and pathogens. Biological control agents may provide good control option under certain conditions (temperature, humidity, length of day) or on certain crops. Most biological control agents are highly perishable, so they need to be handled with care and must be released soon they are received. Its release must be planned for the right time and biology must be thoroughly understood as most species are effective on one or a few species of pests. Beneficial insects have been successfully used to control pests in greenhouses [49] and outdoor specialty crops such as strawberries [50]. Most of the intrinsic problems associated with biological control appear mainly in open areas with arthropod agents, which might emigrate from the plantation leaving the pest behind and attack each other (intraguild predation) rather than the target pest [51], or attack nontarget prey [52]. Biological control can be classified into three basic categories namely classical, conservation, and augmentation [53, 54]:

