The presence of the caterpillars of this moth rarely cause significant damage in gardens and 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.
Control measures are only required if the caterpillars are causing a significant amount of defoliation. If the caterpillars are spotted at an early stage on small plants they can be removed to a larger plant; on larger trees and shrubs whilst some parts of the plant may be defoliated this will have no effect on the long term health of the host plant and so can be tolerated. When handling the caterpillars gloves can be worn as a precaution, although the hairs are visually striking they do not usually cause irritation.
If the egg-covered cocoons, on which this species overwinters, are spotted these could be removed to another host plant elsewhere in the garden.
Chemical control is rarely necessary in gardens, but if caterpillars are too numerous to be removed by hand an insecticide spray could be considered. Control can be achieved by spraying synthetic pesticides such as deltamethrin (e.g. Sprayday Greenfly Killer), lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), cypermethrin (e.g. Py Bug Killer) or the organic pesticide pyrethrum (e.g. Defenders Bug Killer). The older caterpillars are more tolerant of pesticides than young larvae. These products can be used on some edible plants, check the label and ensure instructions are followed.
Plants in flower should not be sprayed due to the danger to bees and other pollinating insects.
Inclusion of a pesticide product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)