Munsell’s research focuses on “natural enemies”: insects such as hoverflies, ladybugs, lacewings, and parasitic wasps. These species are important allies to farmers because they feed on common crop pests such as aphids. However, decades of agricultural intensification have led to the widespread use of monocultures, resulting in the scarcity or even complete absence of key resources such as nectar, pollen, habitat, and diverse prey.
”We often think that pest control requires something we buy or use, but nature has already provided a very effective solution—provided we create the right conditions for it,” Mansell said.
Munsell emphasizes that these beneficial insects require different resources at different times of the year, and no single habitat can satisfy all their needs. Instead, they rely on a combination of multiple habitats—a principle known as landscape complementarity.
Mansell said, “You can think of it like beneficial insects creating a year-round buffet. When resources are abundant, natural enemies can survive, reproduce, and control pest populations. When those resources suddenly disappear, the whole system collapses.”
Flower strips are increasingly being used in European agriculture, but their effectiveness is inconsistent. Flower strips are narrow, artificially planted bands of flowering plants along the edges of farmland, designed to create a semi-natural habitat that supports beneficial insects. However, a review of 75 studies by Mancier shows that many flower strips are ineffective simply due to a lack of suitable flower varieties or improper flowering time. Flower strips specifically designed to support insects’ natural enemies show much better results.
”It’s not enough to just plant some ‘flowering plants’ and leave things to chance,” she said. “The choice of plant species is crucial, especially for insects like hoverflies, which can only exploit certain types of flowers.”
To better understand the interactions between different habitats in agricultural landscapes, Munsell developed an improved population dynamics model using hoverflies and aphids as study subjects. Her modeling results show that woody habitats are particularly important, providing nectar and foraging resources early and late in the growing season, when crop yields are low.
She also showed that agricultural lands themselves can be an important source of natural enemies of pests, challenging the long-held assumption that only semi-natural habitats can make a significant contribution to pest control.
Another important point is the need for continuous management. Incorrectly planned mowing or harvesting can suddenly deprive plants of critical resources, disrupting predator populations at critical times. Adjusting mowing times or staggering fieldwork can prevent such sudden disruptions in resource distribution.
Mansell said, “Farmers don’t need to completely transform their farmland. Small, timely changes—such as delaying mowing for a few weeks—can have a huge impact on predator survival.”
Munsell’s research provides scientific guidance for creating landscapes that promote the survival and proliferation of pests’ natural enemies. By integrating woody plants, carefully designed flower strips, and complementary crops, farmers can enhance natural pest control, reduce reliance on pesticides, and support biodiversity.
Mansell said, “Sustainable agriculture isn’t about going back to the past, but about using modern ecological knowledge to farm more intelligently. When we design landscapes that support the needs of beneficial insects, we create resilient food systems for long-term development.”
Laura Mansell: *The Amazing Lives of Natural Enemies: The Role of Landscape Complementarity in Natural Pest Control*. Supervisor: Dr. A. R. M. Janssen. Co-supervisors: Dr. P. K. J. van Rijn and Dr. J. A. ten Brink.
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Post time: Jun-23-2026
