Today 
In mid-spring, 2mm-long, greenish-brown, adult bay suckers emerge from overwintering. They feed on young bay leaves, turning them yellow and making the edges thicken and curl. The females then lay eggs under the curling edges and the new, young grey insects - which have a fluffy white covering - carry on feeding on the sap, prolonging the problem. Prolific breeding in summer means the symptoms don't disappear.
Solution
Organic
Minor attacks can be tackled by promptly removing all affected leaves. Also, destroy any that fall on the ground, as these can still carry the eggs or adults.
Chemical
Significant attacks are best tackled by spraying the plant with thiacloprid, a systemic insecticide, the moment the symptoms appear. Wait a minimum of two weeks after spraying before using leaves in the kitchen.
