An interdisciplinary approach to protecting UK forests from the biggest killer of spruce in continental Europe, Ips typographus

Ips typographus, the eight-toothed spruce bark beetle, is the most destructive pest of spruce in mainland Europe, with losses of up to 50% reported in heavily infected regions in Belgium and northern France. Over the last 20 years, higher than average temperatures and storm damage have triggered large outbreaks of I. typographus across Europe, increasing the risk of import and natural dispersal into the UK. The UK remained free of I. typographus until 2017, when breeding populations were detected in Kent and then more recently in East Anglia in 2024.

The Epidemiology and Modelling Group in the Department of Plant Sciences has been supporting the response to the outbreak, working closely with an interdisciplinary team of entomologists at Forest Research, policy makers at Defra and the UK Met Office Atmospheric Dispersion and Air Quality Group to understand the potential dynamics and dispersal of the pest into and within the UK. The project utilsed phenological modelling to demonstrate that the climate in the south-east of England is currently sufficiently warm to support two full generations of Ips typographus.

Wind-plume modelling, combined with daily rotator trap data, provided evidence that the source of the primary infestations in the south-east of England were most likely to have been dispersed by wind from infested areas in mainland Europe. The Cambridge modellers have used the UK Met Office’s Numerical Atmospheric-Dispersion Modelling Environment (NAME) to identify the potential pathways for dispersal, directly informing the Scottish Forestry’s Ips typographus management and surveillance strategy of the potential risks to high-value commercial forestry sites. Whilst the project is focussed on I. typographus, the skills and methods developed will also improve our longer-term ability to respond quickly to emerging tree pests and pathogens.