Soft fruit toolbox - Monitoring and alternative control strategies
Monitoring provides a way of alerting growers to potential problems and allows control measures to be applied before the situation becomes harder to control. Alternative control measures are an important part of an IPM strategy and often these alternatives, such as biocontrol, work best if applied early.
The spotted wing drosophila (Drosophila suzukii) (SWD) is an introduced pest to the UK which damages the fruit of many soft fruit and tree fruit species. The James Hutton Institute is part of a AHDB funded UK wide monitoring programme - The Spotted Wing Drosophila Working Group | AHDB. The latest institute results can be read here. A video shows how the traps are maintained in Scotland.
Monitoring traps for the raspberry beetle (Byturus tomentosus) were developed with Sentomol Ltd using chemicals that mimic the flower volatiles and attract the beetles. Threshold beetle numbers in the traps give growers an indication of when pest control treatment is required.
The James Hutton Institute was part of a Plant Health Centre project to monitor a new invasive species, the Brown marmorated stink bug (Halyomorpha halys), using clear sticky traps. The traps sited in locations around Scotland indicated that the stink bug has not yet become established.
Hyperspectral imaging is a technology that could be used to monitor plant stress responses to pests and pathogens. A hyperspectral imaging method has been developed for field-based monitoring of plant stress in raspberry plantations (Williams et al, 2017).
Alternative control (image: mummies)
Biopesticides are derived from natural materials which have pesticidal properties while being safer for the environment. AHDB funded work helped identify potential new biopesticides to use against pest and diseases.
Parasitoid wasps occur naturally in the environment but can be introduced at high densities to polytunnel and glasshouse production to provide good aphid control. Working with Koppert Ltd we have tested several parasitoid wasps in combination. These parasitise two aphid pest species, with 40% success in polytunnels and 80% success in glasshouses.
The entomopathogenic fungus Metarhizium brunneum is widely used to control the vine weevil (Otiorhynchus sulcatus). A joint PhD studentship with Harper Adams University looked at the efficacy of the fungus in different vine weevil populations and found that the efficacy was consistent between insect populations (Morera-Margarit et al., 2020).