Biological control involves the mass-production and release of natural enemies such as parasitoids and predators to control pest insects in an environmentally sound manner. Radiation is used to increase the applicability, cost-effectiveness and safety of rearing, shipping and deploying such natural enemies.Augmentative biological control, involving the supplemental release of natural enemies of insect pests, can complement the sterile insect technique (SIT) in area-wide integrated pest management programmes. While under the SIT sterile males are predominantly released at the adult stage, many of their natural enemies attack them in immature stages. This means that using both control techniques at the same time can often produce mutually supporting enhanced results. Additionally, by-products from insect mass rearing facilities can be used in production processes related to augmentative biological control programmes.