Vitax Gardening Monitoring Trap Fruit Tree Grease 200g Easy to use, brush-on monitoring trap Prevents wingless female moths climbing trees to lay their eggs Apply in Autumn (September/October) and renew in February Winter Moths are the scourge of fruit trees. They lay their eggs in tree bark crevices and the resultant larvae and caterpillars - easily recognised by their green colour with pale lines on the side and a darker one along the top - will feed on virtually any tree or shrub and can be a serious pest in apple trees and orchards. Vitax Fruit Tree Grease is the answer. It's a traditional, brush-on monitoring trap for winter moths and prevents damage to fruit trees.