Approaches of Biological Control: Conservation

Conservation biological control basically means keeping alive and enhancing the effectiveness of those natural enemies that are already present. Many conservation approaches are easily integrated into production regimens and can be very effective. Often, providing a missing requirement can make the difference for a natural enemy. For example, some parasites can benefit from providing non-prey food sources, such as flowers that might produce nectar or pollen. Alternatively, nesting sites for social wasps can lead to increased population persistence and, as a result, greater predation against certain pest species. A study by Landis and Marino (1996) has shown that the Ichneumonid parasite Eriborus terebrans can maintain populations and provide parasitism against European corn borer (Ostrinia nubilalis) in locations near wood lots; the parasite benefits from moderated temperatures provided by the wood lots, which are absent from many crop systems.

Another very significant factor in conservation biological control is reduction of pesticides. Although pesticides can kill pests, they also can kill many natural enemies. By using fewer applications of pesticides, altering the timing or formulation of the pesticides, or using "softer" pesticides, which may be less toxic, natural enemeis can be conserved.