Caterpillars (cabbage whites and others)
Pest Butterfly and moth larvae that chew leaves, especially on brassicas.
What to look for
Holes in leaves, droppings, and yellow-green caterpillars or clusters of yellow eggs on the underside of brassica leaves. Plants can be stripped to the veins in days.
When: May to October, with two or three waves of butterflies.
How to prevent it
- Cover brassicas with fine mesh or butterfly netting from planting, with no gaps at the edges.
- Check the undersides of leaves weekly from May and squash eggs.
- Encourage birds, which feed caterpillars to their young.
How to deal with it
- Pick off caterpillars by hand and squash the eggs.
- Remove badly damaged outer leaves and use the rest.
- Clear old stalks in autumn, as chrysalises overwinter in debris.
Crops it affects
If you choose to use any treatment, use only products approved for UK home gardens, follow the label and avoid spraying open flowers. See all pests and diseases.