Beneficials, also known as biocontrol agents, are natural enemies or competitors of crop pests. Some beneficials have been able to be bred in commercial insectaries and can be purchased and released into crops to control specific pests. The benefit of using commercially reared beneficials and encouraging natural beneficials to assist in the management of crop pests is that reliance on chemical control options is reduced. Additionally, chemical residues are minimised and there are no withholding or worker re-entry periods. Examples of beneficial insects, mites, and nematodes that can be purchased for release into crops include:

• Aphidius - parasitoid of aphids
• Cucumeris - predatory mite of thrips
• Encarsia - parasitoid of whitefly
• Entomopathogenis nematodes - insecticidal nematodes which attack a range of insect pests
• Hypoapsis - predatory mite of fungus gnats
• Green lacewing - predator of aphids and moth eggs
• Montdorensis - predator of thrips
• Persimilis - predatory mite of two spotted mite
• Trichogramma - egg parasitoid of a range of insect pests

Biological control agents are released into crops in a number of ways. These can be placed in crops as adults, as pupae in moth eggs, in satchels with food, on a card, or spread in a carrier. Additionally, there are non-insect beneficial organisms that can be applied as a spray to crops. These include Heliothis Nuclear Polyhedris Virus (NPV) and Bacillus thuringiensis (Bt). Heliothis larvae infected by a NPV spray turn dark, die, and disintegrate, releasing a virus-laden fluid. Other larvae may be infected from eating foliage contaminated by a previously infected and killed larva. But can affect many caterpillar species. Larvae have to eat a lethal dose from contaminated foliage to be affected by the bacteria. While larvae usually stop feeding immediately after ingestion (and therefore crop damage stops), it may take several days before the caterpillar is killed.