Trees which have a dense canopy and vigorous shoot growth tend to support greater populations of caterpillars. If shoot growth then ceases when caterpillars are young, due to water stress and/or a heavy fruit load, the caterpillars tend to move to feed on fruits, especially those in clusters, and damage intensifies.
- Avoiding this situation by tree management reduces losses.
- The cultural control approaches recommended for codling moth are likely also to be effective in controlling summer fruit tortrix moth, though hygiene measures need to be modified to suit this particular species.
- Furnishing the trees with artificial refuges for earwigs and other insect predators is likely to help reduce young caterpillar populations.
- Ideally, a refuge should be provided in each tree. This may simply be some extra lengths of hollow tree tie round the stake.
- In orchards with high tree densities, it is likely to be impractical to provide more elaborate refuges such as half of a plastic drinks bottle containing a roll of corrugated cardboard.