Plant diversification impact on the oviposition response of a predatory bug in a laboratory set-up

Summary

Crop diversification can improve biological pest control, by providing resources and habitat to enhance the performance of natural enemies. The polyphagous black bean aphid (Aphis fabae) is a major pest in sugar beet and also an important pest in faba bean. Faba bean is potentially suitable for intercropping with sugar beet due to its beneficial attributes such as nitrogen fixation. Biological pest control, in cases where the same pest attacks both crops, thus depends on the performance of natural enemies present in those crops. To investigate the potential benefits of crop diversification on predator performance, a laboratory experiment was conducted to study the reproductive response of the predatory bug Orius majusculus, in mixed and single crop setups with faba bean and sugar beet plants. Number of eggs laid and choice of reproductive site by O. majusculus was assessed. Orius majusculus laid nearly twice as many eggs in cages that contained both faba bean and sugar beet plants, compared to cages that contained just one of the plant species. In conclusion, faba bean has characteristics suitable, in combination with sugar beet, for an intercropping system, by supporting reproduction of O. majusculus, thus improving the biological control of the black bean aphid. Understanding arthropod ecological interactions in crop diverse agroecosystems makes a significant contribution to the development of resilient cropping systems.