Larger wildflower plantings increase natural enemy density, diversity, and biological control of sentinel prey, without increasing herbivore density

Abstract

1. An important means of conserving beneficial insects in resource-limited habitats is to meet their ecological requirements, which may be achieved by providing areas containing flowering plants that bloom throughout the season, but little is known about the importance of wildflower plot size for supporting natural enemies or the biological control they provide.2. Wildflowers were established in plots of sizes ranging from 1 to 100 m 2 , and found that natural enemy density, group richness, and diversity of natural enemy groups increased with plot size.3. The density of insect herbivores was lower in all flower plots than in the control samples, whereas the diversity of herbivore groups was significantly higher in flower plots.4. Comparing population growth of sentinel soybean aphids (Aphis glycines Matsumura) among plot sizes, aphid colonies were smaller as plot size increased.5. Providing beneficial insects with flowering resources resulted in significantly more natural enemies and greater pest control than in smaller flower plots or mown grass areas.6. These results indicate that the density, diversity, and function of natural enemies are sensitive to the size of wildflower plantings, even at relatively small scales. Therefore, larger wildflower plots are more suitable for the conservation of beneficial insects and their provision of natural pest control.

Manipulating field margins to increase predation intensity in fields of winter wheat (Triticum aestivum)

“…). The presence of flowers adjacent to crops can promote a higher level of pest control compared to grass (Blaauw and Isaacs ; Balzan and Moonen ). This is usually attributed to the presence of floral resources (pollen, nectar and sometimes extra‐floral nectar) that may be necessary during particular life stages of natural enemies such as hoverflies, lacewings, ladybirds and some spiders (Wäckers et al.…”

Levantamento populacional de inimigos naturais na cultura da manga (Mangifera indica L.)

“…A diversidade de espécies de plantas pode aumentar consideravelmente a densidade, riqueza e diversidade de espécimes de inimigos naturais e, consequentemente, propiciar melhores resultados no controle biológico de determinadas pragas agrícolas (Giller et al, 1997;Blaauw & Isaacs, 2012).…”

Does Landscape Complexity and Semi-Natural Habitat Structure Affect Diversity of Flower-Visiting Insects in Cucumber Fields?

“…Size of habitat directly affect the resources to support the insect population, for example patch size of flower plants influenced the composition of insect pollinators (Sowig, 1989). Other research by Blaauw & Isaacs (2012) also showed that patch size of wildflower had positive relationship with species richness of predator and parasitoid on agricultural landscape.…”