Research and Guidance
The large pine weevil (Hylobius abietis) is the most serious pest of newly planted or naturally regenerating woodland trees on restocking sites in the UK and Ireland. On affected sites, in the absence of protective measures, losses of replanted trees will average around 50%, but in the worst cases all trees can be killed. The need to find alternatives to the use of synthetic pyrethroid insecticides led to a collaborative research effort across the UK forest industry which investigated over 100 different approaches on 22 different trials sites.
Several lower toxicity insecticides were identified that can effectively protect trees,, as well as non-chemical approaches that may work when on-site populations are predicted to be lower.
Three scientific papers have been produced by Forest Research fully reporting on the results of these experiments, and they are freely available as follows:-
Acetamiprid used to prevent Hylobius abietis damaging young trees poses a very low risk of causing water contamination provided good forestry practices are followed.
Acetamiprid, chlorantraniliprole, and in some situations the physical barriers MultiPro® or Kvaae® wax, can be alternatives to traditional synthetic pyrethroid insecticides for the protection of young conifers from damage by the large pine weevil Hylobius abietis
Are there viable chemical and non-chemical alternatives to the use of conventional insecticides for the protection of young trees from damage by the large pine weevil Hylobius abietis L. in UK forestry?
Two trade journal articles have also been produced that summarise these scientific papers:-
Willoughby, I.H. and Moore, R. (2021). Defending our trees. What’s the latest in the battle against Hylobius? Trees, summer 2021, 20-21. www.charteredforesters.org
Willoughby, I.H. and Moore, R. (2020). Hylobius attack: other ways of protection. Forestry and Timber News 102, 64-65. https://www.confor.org.uk/news/ftn-magazine/
Integrated Management of Hylobius
The latest guidance on the integrated pest management of the insect Hylobius abietis is contained in this Forest Research Report. It incorporates all the most recent research findings on alternatives to the use of conventional pesticides for protecting trees from Hylobius damage. In addition, as a separate Appendix, it summarises knowledge and guidance on the safe use of the insecticide acetamiprid, which is increasingly being used as an alternative to cypermethrin.
