There are an increasing number of non-native pests and pathogens that are impact the UK’s trees. The decline in a particular tree species will impact a wide range of other species that use that trees species as well as driving changes in ecosystem functions.
Reduction in the availability and quality of plant food resources through arable intensification and habitat fragmentation has been cited as a major cause of the decline in pollinators in the UK and worldwide, and is likely to have a negative impact on the activity and abundance of natural enemy species that rely on floral resources in their adult life stages. Many pollinator and natural enemy groups disperse over large distances in search of pollen and nectar, and this might be exacerbated in intensively-managed systems with low resource diversity. Alternative management systems that lead to increases in resource availability and quality for these insects are therefore likely to promote both diversity, through niche differentiation, and fitness, by reducing the need for insect foraging over large distances. Thus, management to increase within-field and farm-scale vegetation diversity is one option to combat declines in pollinator populations and promote numbers and activity of natural enemies.
We have been breeding raspberry varieties for Scotland, UK and Europe for > 40 years. A key trait (conferred by one or more major resistance genes) is for resistance to the main aphid pest, the large raspberry aphid. This strategy has been very successful but over decades the pest has co-evolved resistance-breaking biotypes. We are now at a ‘tipping point’ where the pest can overcome resistance genes in the crop faster than plant breeders can introduce new types of resistance (typically taking 10+ years).
