Pest categorisation of Dendroctonus micans

Abstract

The Panel on Plant Health performed a pest categorisation of the great spruce bark beetle, Dendroctonus micans (Kugelann), (Coleoptera: Curculionidae, Scolytinae), for the EU. D. micans is a well-defined and distinguishable species, recognised mainly as a pest of spruce (Picea spp.) and pine (Pinus spp.) in Eurasia. Attacks on other conifers (Abies spp., Larix decidua, Pseudotsuga menziesii) are also reported. Supposedly originating from north-eastern Eurasia, D. micans has spread westward and is now distributed throughout the EU (22 Member States). It is a quarantine pest listed in Annex IIB of Council Directive 2000/29/EC for Greece, Ireland and the United Kingdom (Northern Ireland, Isle of Man and Jersey) as protected zones. Wood, wood products, bark and wood packaging material of the conifers genera listed as hosts are considered as the main pathways for the pest, which is also able to disperse several kilometres by flight. The sib-mating habits of the species allow each single female to start a new colony on her own. The pest’s wide current geographic range suggests that it is able to establish anywhere in the EU where its hosts are present. The beetles attack living trees and usually complete their life cycle without killing their host, except under epidemic conditions at the limits of their distribution range, where hundreds of thousands of trees can be killed. Sitka spruce (Picea sitchensis) is particularly susceptible. Biological control using the very specific predatory beetle, Rhizophagus grandis, is a widespread and efficient option that has been implemented in all areas suffering from outbreaks. It is complemented by sanitary thinning or clear-felling. All criteria assessed by EFSA for consideration as potential protected zone quarantine pest were met. The criteria for considering D. micans as a potential regulated non-quarantine pest are not met since plants for planting are not the main pathway.