Crop Diversity Supports Beneficial Insects that Prey on Crop Pests
A study in China, published in Annals of the Entomological Society of America, found that polyculture supports increased populations of natural-enemy insects that prey on crop pests. The three-year study measured plant and insect biomass in plots with one to 16 crop species planted. Researchers found that the more species of plants in a plot, the more species of insects found there. However, they also found that the more plant species in the plot, the higher the biomass of natural enemies. In other words, the ratio of natural enemies to pests increased as the diversity of crops planted increased. The researchers concluded that increasing crop diversity could help support biocontrol of crop pests by natural enemies.