Great spruce bark beetle regulations, information and advice for Scotland
The great spruce bark beetle (Dendroctonus micans) is a common pest of spruce and pine in mainland Europe but is not native to the UK. It tunnels into the bark of living trees to lay its eggs. The larvae then feed and develop, forming galleries that weaken, and in some cases kill, the host tree. The beetle was first detected in Wales in 1982 after it was accidentally introduced, most likely via a consignment of imported timber, a decade beforehand.
In the UK, Norway spruce and Sitka spruce are the primary hosts of this pest. Sitka spruce is Scotland’s most important commercial tree species and monitoring spruce health is a high priority for us.
Trade of conifer roundwood to the island of Ireland has been enabled by maintaining the status of the conifer bark beetle Pest Free Area (PFA) in western Scotland as free from D. micans, Ips cembrae and Ips sexdentatus bark beetles. Due to findings of the Ips cembrae bark beetle in the PFA, no phytosanitary certificates for export of conifer roundwood are currently being issued.
Known spread
D micans is now an established pest in southern Scotland and is slowly extending its range northwards. The beetle is a capable flyer but long distance spread is also known to occur through the movement of infested roundwood. The D. micans distribution map in Scotland shows the Pest Free Area and the latest confirmed distribution of D. micans in Scotland. We're working with the timber sector to promote the ‘Ditch the Debris’ message to reduce the risk of moving infested material into the Pest Free Area via timber haulage.
Control
Once D. micans is detected, effective levels of control are achieved through the release of an extremely specific predatory beetle, Rhizophagus grandis, the supply of which is provided by a breeding facility run by Forest Research with licence approval granted from NatureScot. Although release of R. grandis currently offers a highly effective management solution it does not eradicate D. micans or prevent further spread, vigilance remains necessary to detect or treat new infestations and to track whether climate change alters the dynamics between R. grandis and D. micans.
Report a sighting
If you own or manage a woodland, please be vigilant and inspect your woods regularly.
Please report suspicious symptoms on any tree in Scotland to TreeAlert through the general enquiry webform.
The webform will ask you for your contact details, the location of the sighting, and clear photographs of the affected tree(s) in context and the symptoms. For more information on what to include in your report, visit the TreeAlert - What To Do page.
Once your report is submitted, diagnosticians at Forest Research will review it. They may contact you to request additional details.