Control of the Pine Weevil, Hylobius abietis L., and of Hylastes species

Dipping the tops of plants, prior to planting, in a 5 per centoil-based emulsion formulation of DDT has given good controlof Hylobius but does not control Hylastes and may involve damagedue to phytotoxicity in some circumstances. Experimentationwith newly introduced water-based formulations of DDT and BHCconfirmed earlier findings that there are few significant differencesbetween possible materials. The need to dip whole plants inorder to control Hylastes, with minimum risk of phytotoxicity,has led to the use of 1.6 per cent water-based BHC on a fieldtrial scale with promising results.