Introduction Many orchard pests are attacked by beneficial insects or mites and by various fungal, bacterial and viral agents. Predators are generally as large or larger than the prey they feed on. They are quite capable of moving around to search for their food, and they usually consume many pest insects during their lifetime. Lady bird beetles, lacewings and syrphids are examples of insect predators. One or more parasitoids grows and develops in or on a single host.
Most parasitic insects are wasps or flies.
Adult parasitoids do not usually feed on insects, but are highly mobile, laying eggs in many hosts. Aphids, leafminers and leafrollers and other caterpillars are often attacked by parasitic insects. Beneficial insects and mites can help prevent or delay the development of pesticide resistance in orchards by reducing the number of pesticides require to control a pest. They will also feed on the resistant pests that survive a pesticide application. Table 1 lists common beneficial insects and mites and their characteristics.