Sowing a mixture of alfalfa modulates the population density of alfalfa pests

Alfalfa is an important forage crop, referred to as the “king of forage”. With the development of the alfalfa industry, pest damage in alfalfa fields had increased rapidly. Therefore, ecologically based pest management strategies have gained importance in habitat management. In the present study, six varieties of alfalfa were used in 18 treatments sowing either mixture or monoculture, which was aimed to determine the effects of mixture sowing of alfalfa on pest and natural enemies. The results showed that mixture sowing decreased the population density of aphids and enhanced the population density of lady beetles. The minimum population density in mixture sowing alfalfa was 149 individuals per straw, whereas the maximum population density in monoculture alfalfa was 823 individuals per straw. However, mixture sowing had no significant effects on thrips. These results provide important experiment data to support the development of the alfalfa industry and suggest planting patterns for integrated pest management.