The European winter moth as a pest of filberts: Damage and chemical control

Different chemicals and two spray timing dates were evaluated for control of the European winter moth, <i>Operophtera brumata</i> (L.) in filbert orchards of Oregon. Data showed that endosulfan, carbaryl, phosalone, diazinon and fenvalerate were effective against this pest. A <i>Bacillus thuringiensis</i> product, Thuricide HPC was found to be ineffective. The timing of the spray treatment was critical. Sprays applied at 90 - 95% egg hatch (April) were much more effective than the sprays applied at 50 - 60% egg hatch (March). The spray timing seemed to be less critical for fenvalerate treatment, which was equally effective at both treatment dates.The damage caused by <i>O. brumata</i> to filbert trees is described