Slug damage to leaves is clearly visible to any observer. As a result, the photosynthetic activity of the plants is often greatly diminished and their subsequent development impaired. Feeding activity during the seedling stage often leads to the death of young plants as a result of the destruction of the tip of the embryo. In most cases this happens before the seedling has reached the soil surface. Such damage usually requires further seeding or, in a worst-case scenario, recultivation of the field.