Influence of wheat-walnut intercropping on the Sitobion avenae and its predatory natural enemies

Abstract

Intercropping is widely applied all over the world, and it often causes significant changes in the number of arthropod communities. Walnut-wheat intercropping systems are commonly applied in Southern Xinjiang of China. But it is still not clear how wheat-walnut intercropping influence pest and natural enemy populations, and their ratio in wheat fields. To clarify this question and provide guidance to pest management, field surveys were conducted in Xinjiang during 2017–2019. Three intercropping treatments were tested, which were wheat-walnut 10:6, 25:6, and monoculture wheat. Our results showed that the abundance of predators (mainly ladybeetles and lacewings) increased in wheat under wheat-walnut intercropping systems (especially in intercrop treatment 10:6). Compared with monoculture wheat, the ratio of predators to Sitobion avenae was not enhanced in wheat-walnut intercropping fields. S. avenae populations increased in the walnut intercropped wheat fields. The intercropping system was not beneficial to S. avenae control in wheat fields. Different measures should be taken to strengthen the control of S. avenae in walnut intercropped wheat fields.