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NC State Extension

Biological Control With Predators and Parasitoids


Biological control: a ladybeetle eating aphids on tomato plantWhat is Biological Control?

Biological control (or “biocontrol”) is a pest management strategy that can benefit both conventional and organic agriculture. By enhancing the role of natural enemies, the negative impact of a pest on a crop is reduced.

Biological control can refer to the augmentation of native natural enemy populations as well as the introduction of non-native natural enemies. Although a few early efforts at non-native biological control created unexpected problems (such as the introduction of the cane toad to Australia), modern biological control entails a much more sophisticated understanding of ecological communities. Today, biological control is subject to strict regulations and testing to ensure that introductions can be done without disrupting native ecosystems.


Benefits

One benefit of biocontrol is reduction in pesticide use, which can reduce input costs, enhance ecosystem services (e.g. pollination), and protect environmental and human health. For labor-intensive crops such as many tree fruits and vegetables, reductions in pesticide use also allow more time in the field to harvest or manage plants (due to pesticide re-entry (aka restricted-entry) intervals (REI) and preharvest intervals (PHI)). Furthermore, by reducing the use of pesticides, the selection pressure on crop pests is reduced and the development of insecticide resistance is delayed.

High-value vegetables grown in North Carolina have a low tolerance for damage. This has resulted in a high dependence on chemical control, especially for direct pests that feed on fruit itself (e.g. stink bugs and caterpillars). For indirect pests that feed predominantly on foliage (e.g. spider mites, aphids, thrips), there is a higher tolerance for damage and more time for biological control to occur. For this reason, biocontrol can be highly effective for indirect pests but is more challenging against direct pests.


Biological Control for Specific Pests


Additional resources