Adult weevils must come in direct contact with the insecticide spray to be killed. For deciduous tree fruit crops, a butt drench in spring is recommended. Apply the insecticide at the crotch of the tree and around the base. Time the application to coincide with the first evidence of weevil presence - scalloping of lower leaves. One spray, if thoroughly applied over the infested area, should give protection from the spring emergence of weevils.
Low volume misting at the base of trees is ineffective.
For this butt drench method of control to be most effective, remove alternative routes into trees - such as low hanging limbs and weeds growing into the canopy. These often result in the concentrated feeding of weevils in hot spots. Such bridges should be removed at the start of the season by using herbicides under drip lines, and slashing and pruning. For grapevines, it is impractical and less effective to use the butt drench method. Foliar applications of the synthetic pyrethroid fenvalerate, applied at night, are recommended.