Biological Control in Agricultural Ecosystems

Biological control harnesses the natural interactions between arthropods, pathogens and plants to suppress pest populations in crop systems. In agricultural landscapes global adoption spans three general approaches: classical biological control, in which exotic natural enemies are introduced to suppress invasive pests; conservation biological control, which seeks to manage habitats so that indigenous predators, parasitoids and pathogens persist and flourish; and augmentative releases that bolster enemy numbers at critical times. Across cereal, cotton, horticultural and perennial systems, practitioners use non-crop refuges, flower strips, cover crops and semi-natural habitats to sustain natural-enemy communities. Key agent groups include predatory beetles, lacewings and syrphid flies, together with parasitoid wasps that attack aphids, lepidopteran and coleopteran pests. Advances in landscape ecology demonstrate how crop diversity, phenological synchrony and spatial arrangement shape enemy spillover into fields, while studies in transgenic and insecticide-treated crops reveal that pesticide regimes can undermine or enhance top-down control. Economic analyses underline the cost–benefit trade-offs of reduced insecticide use versus augmented ecosystem services. Emerging tools such as stable isotope tracing, network modelling and high-resolution habitat mapping are refining our capacity to predict when and where biological control will be most effective. As agriculture intensifies, integrating biological control with precision irrigation, soil health and climate-smart practices offers a pathway to resilient, productive and environmentally benign farming.

Research from Nature Portfolio

Research in a Bt cotton ecosystem documented robust top-down suppression of cotton aphids by indigenous natural enemies, with parasitic wasps, lady beetles and spiders together reducing aphid densities by over 60 percent at key growth stages. Detailed field experiments using exclusion cages showed that the efficiency of biocontrol agents peaked during early to mid-season, coinciding with the highest densities of both pests and natural enemies on the crop. These findings emphasise that even in genetically modified systems, conservation of diverse enemy guilds can deliver substantial pest regulation and reduce reliance on chemical insecticides.

Biological Control in Agricultural Ecosystems publication trend

The graph below shows the total number of articles in biological control in agricultural ecosystems across all publications each year (not limited to Nature Index journals).

Technical terms

Conservation biological control: The management of non-crop habitats and farming practices to conserve and enhance indigenous natural enemies of crop pests.

Augmentative release: The supplemental introduction of mass-reared natural enemies into the field to boost biocontrol at critical pest outbreak periods.

Classical biological control: The deliberate importation and establishment of non-native natural enemies to control invasive pests in new environments.

Natural-enemy spillover: The movement of predators or parasitoids from source habitats into crop fields where they contribute to pest suppression.

Top-down control: Regulation of pest populations by predators, parasitoids or pathogens acting from higher trophic levels.

References

1. Characterization of the natural enemy community attacking cotton aphid in the Bt cotton ecosystem in Northern China. Scientific Reports (2016).
2. Pesticide Regime Can Negate the Positive Influence of Native Vegetation Donor Habitat on Natural Enemy Abundance in Adjacent Crop Fields. Frontiers in Ecology and Evolution (2022).
3. Effects of Aphid Density and Plant Taxa on Predatory Ladybeetle Abundance at Field and Landscape Scales. Insects (2020).
4. Adjacent habitat type affects the movement of predators suppressing soybean aphids. PLOS ONE (2019).