This chapter discusses the application of biological control in the management of forest insect pests in Colombia. It includes the use of egg and larval parasitoids, predators and microbial control agents, used for the control of Pinus and Eucalyptus pests in the framework of Insect Pest Management (IPM). An important egg parasitoid species that is mass-reared in Colombia is Telenomus alsophilae Viereck (Hymenoptera: Scelionidae). But many other natural enemies are being managed through conservation by protecting plants that provide important resources for their reproduction and performance. Among entomopathogenic biological control agents, the most commonly used are Bacillus thuringiensis to control Lepidopteran larvae and Beauveria bassiana to control various insect pests such as loopers, mirids and weevils. Research is being developed to find effective biological control methods against leaf cutter ants which are currently the only insect pest problem that is controlled with chemical insecticides in Colombia. Research is ongoing to develop effective biological control to manage leaf cutter ants, which are currently the only forest insect pests in Colombia controlled by chemical pesticides.