The caterpillars of this moth can be found feeding on plants at all times of the year but are most common between May and October.  

• Holes are eaten in the foliage and flowers of a wide range of plants, including unopened flower buds, frequent hosts include chrysanthemums, red valerian and barberry 
• Young growth at the shoot tips is particularly favoured
• The caterpillars are up to 45 mm long (1¾ in) and vary in colour from brownish yellow to bright green
• They hide during the day, emerging to feed at night

It is only occasionally that caterpillars of this moth cause significant damage in gardens; it can usually be tolerated. Caterpillars and associated moths are important as a food source for other garden wildlife and so should be preserved where possible.

• Where possible tolerate populations of caterpillars, as butterflies and moths are an important part of the garden ecosystem
• Encourage predators and other natural enemies in the garden such as birds, wasps, hedgehogs and ground beetles
• Check plants regularly for the presence of larvae and remove by hand where practical
• Caterpillars can be removed to alternative host plants where damage is less undesirable (e.g. common nettle, hop or bramble) or larger host plants where their feeding will have no effect on the long term health (e.g. hazel, birch or oak)