Biological Crop Protection: A New ‘Slow Down-Speed Up’ Strategy for Aphid Management

Abstract

Aphids are important insect pests of a wide range of crop plants, causing over $1billion of crop losses annually. For field crops, the ‘standard’ method of managing aphids has been to apply synthetic chemical insecticides. While this approach has been an effective method of control for many years, overreliance on insecticides has led to the evolution of insecticide resistance in several key aphid pests. There are also increasing concerns regarding the environmental impact of insecticide use, leading to many products being withdrawn from sale. This has left farmers with few effective options for controlling the aphid pests that have now become a major threat to global crop production. A sustainable aphid management strategy that can help to protect harvests from pests is urgently needed to address this threat.

Description

To achieve more sustainable crop protection methods that are less prone to resistance, farmers should not over-rely on any one intervention. Diversification of crop protection can be achieved through integrated pest management (IPM), which promotes the use of an appropriate combination of environmentally sustainable methods of pest control. These can include pest resistant crop varieties, the use of natural enemies, and 'biopesticide' products based on beneficial microbes or natural products. Unfortunately, as farmers have been so reliant on synthetic chemical insecticides as their principal form of pest control, there is currently no effective IPM system in place for most aphid pests in field crops. The development of IPM for aphid pests has largely been restricted by a lack of new pest control methods being developed and an understanding of how control methods can be used together.

This project aims to develop the tools and knowledge needed for an effective IPM system to manage aphid pests of field crops using a model system comprising of Brassica plants, the peach potato aphid (Myzus persicae) and parasitoid wasps such as Diaeretiella rapae. We will use this model system to test the hypothesis that plants with partial resistance ‘slow down’ aphid development and increase their susceptibility to biological control agents while pest control can be ‘sped up’ using cis-jasmone to induce plant defence priming to attract and retain parasitoid wasps within a Brassica crop.