Genotypic diversity of soybean in mixed cropping can affect the populations of insect pests and their natural enemies

In order to determine the potential benefits of soybean genotypic diversity for the population densities of major insect pests and their natural enemies, the field treatments were compared in monocultures and mixed cropping systems that included five soybean cultivars. The results indicate that monocultures tended to have similar density of aphids, Aphid glycines Matsumura, but a higher density of leafhoppers, Empoasca flavescens (Fab.), than mixed cropping systems. The mixed cropping array significantly increased the population density of some generalist natural enemies, including ladybeetles, lacewings and hoverflies, to varying degrees. These findings suggest that mixed cropping systems may be more effective to control insect pests than monocultures in soybean fields, and these findings offer a practical implication in modern soybean agricultural industry.