SCOTTISH growers have been put on alert for a new insect threat to their crops – the brown marmorated stink bug.

The species – formally titled Halyomorpha halys – has not yet been detected north of the border, but it has been intercepted several times at UK ports and now has a confirmed presence in the south of England. Experts have warned that the unfussy bug poses a threat to a wide variety of plants, and thus has the potential to become a serious problem for the UK’s agricultural, horticultural and forestry industries.

The stink bug can already be found on every continent in the Northern Hemisphere, including North America and mainland Europe, and has a wide host range including soft and tree fruit, field vegetables, and ornamentals.

Scientists from the James Hutton Institute, Scotland’s Rural College and SASA have placed sex pheromone traps at strategic points around Scotland, including near transport hubs and in soft fruit growing areas, to attract the bug if it is present, and developed a DNA fingerprinting method to help distinguish it from similar, less damaging species.

Fortunately, the stink bug has not been found in any of these Scottish traps – but using climate modelling, researchers have highlighted that plants grown in polytunnels may provide key areas for the establishment of the pest should it arrive, and therefore this should be the focus of continued monitoring.

JHI plant scientist, Gaynor Malloch, who is lead author of the report into the threat of the stink bug, said: “Under the current outdoor temperatures experienced in Scotland, it is unlikely that the bug could successfully complete a generation and become established as a pest if it remains outdoors. However, there is a possibility that it could establish if it were to spend some time indoors (e.g., in the winter months) as well as outdoors.

“If the bug appears, we would expect establishment to be slower in Scotland than the rest of the UK and there is, therefore, the potential to attempt eradication or to manage individual outbreaks carefully to prevent spread.

“Growers are already very vigilant when it comes to monitoring pests and diseases in their crops and we hope that they will keep a close eye out for this particular pest and report it to the authorities if suspected.”

The research has developed identification methods to enable a future diagnostic service to be provided, the logistics of which are currently under discussion. The results also provide data that looks at the potential of different locations to support a permanent population of the bug under current and future climates and helps to identify areas most suited for future monitoring studies.

The study was funded by Scotland’s Plant Health Centre and a summary of the research is available on the Plant Health Centre website: www.planthealthcentre.scot/publications.

To report suspected findings of the brown marmorated stink bug in Scotland, please contact the Scottish Government’s Horticulture and Marketing Unit: hort.marketing@gov.scot