Wasps: natural biological control of caterpillars and other agricultural pests

Wasps are among the most important natural enemies of agricultural pests. Many species act as predators or parasitoids of insects that damage crops, especially lepidopteran larvae (caterpillars) that attack leaves, flowers, and fruit. Thanks to this behavior, wasps contribute to natural biological control, reducing the need for chemical insecticides in agriculture.

Helicoverpa sp. larvae captured and stored by Polystes wasps in a commercial cannabis crop. Source: Gus Garzón, Cassabis.org

How Wasps Control Pests

Wasps regulate pest insect populations through two main mechanisms

Predatory Wasps

Predatory wasps capture insects to feed themselves or their larvae. Some social species, such as those in the genus Polistes, actively collect caterpillars and other phytophagous insects, helping to reduce populations of defoliating pests in crops and orchards.

Polistes Wasp preying on Helicoverpa larvae in Cannabis. Source: Gus Garzón, Cassabis.org

Parasitoid Wasp

Parasitoid wasps lay their eggs inside or on the host insect. When the larvae hatch, they feed on the pest insect's body until it dies. This mechanism is very effective against butterfly and moth caterpillars that affect numerous agricultural crops. Among the most important wasp families used in biological control are Braconidae, Ichneumonidae, and Trichogrammatidae, which are widely studied and used in pest control programs.

Benefits of Wasps in Agriculture

The presence of wasps in agroecosystems offers multiple benefits: natural control of insect pests, reduction in pesticide use, greater ecological balance in crops, and support for integrated pest management (IPM). Furthermore, in agricultural systems with greater plant diversity, populations of natural enemies such as wasps tend to be more abundant and efficient in pest control.

How to attract beneficial wasps to your crops

To encourage the presence of wasps on your farm or in your garden, it is recommended to: plant flowering plants that produce nectar (cilantro, basil, fennel), maintain polycultures or agroforestry systems, preserve living fences and natural vegetation, and avoid broad-spectrum insecticides. These practices help create a favorable environment for beneficial insects.

Polistes nest on cannabis. Source: Gus Garzón Cassabis.org

Conclusion

Wasps are natural allies of sustainable agriculture. Their ability to prey on or parasitize insect pests, especially lepidopteran larvae, contributes to the balance of agroecosystems and the biological control of pests without resorting to chemicals. At Cassabis.org , we promote strategies for Sustainable Agroindustry, Corporate Social Responsibility, and Integral Human Development. Keywords: biological pest control, beneficial wasps, natural pest control.

References

Greathead, D. J. (1984). Parasitoids in classical biological control.

Quicke, D. L. J. (2014). The Braconid and Ichneumonid Parasitoid Wasps.

Southon, R. J. et al. (2019). Social wasps as biological control agents of crop pests. Proceedings of the Royal Society B.

Van Driesche, R., & Hoddle, M. (2016). Biological Control of Insect Pests.