Brown Tail Moth Caterpillars

What is a Brown Tail Moth?

The Brown Tail Moth is an insect native to the UK. They are found mostly in Southern England and Wales and in some coastal regions further north.

Adults are white with visible brown hairs on the end of their abdomen. The caterpillar is dark brown and has two distinct orange/red spots on its back towards the tail.

Please note that we do not provide a treatment for Brown Tail Moths.

Why is it a pest?

The caterpillars have small hairs on their bodies which break off easily and can irritate the skin which should be treated with warm, soapy water and calamine lotion. If the hairs get into the eyes or throat. a doctor should be seen.

Caterpillars also eat the buds and leaves of trees and shrubs and can cause total defoliation.

Life Cycle

After the leaves have fallen from trees in the winter, you may see silken ‘tents’ attached to small branches. Each tent can contain up to 2000 caterpillars. These tents are easily seen in the winter. Caterpillars can infest any tree but they favour apple, oak, cherry, hawthorn, rugose rose and bayberry.

• Mid-July - the moths mate and lay their eggs, covered in small brown hairs, on the underside of leaves and bushes.
• Late Summer - in August/September the eggs hatch and the caterpillars feed on the foliage, turning the leaves a brown ‘scorched’ colour.
• Winter - caterpillars weave their web-like tents which they use to hibernate.
• Late Spring - caterpillars emerge from hibernation to feed on the foliage.
• Late June - the caterpillars pupate, turning into black chrysalides.
• Mid-July - the chrysalides hatch into adult moths.

Prevention and treatment in early summer

The caterpillars are most active in May and June. Insecticides based on permethrin or pyrethrum (available from Garden Centres and Hardware shops) can be helpful but it is very important that you follow the manufacturer’s instructions and that you wear protective clothing. If in any doubt, please contact a qualified pest control contractor. However, this is likely to be expensive and not necessarily completely effective, particularly in large trees.

Prevention and treatment in autumn and winter

A more effective method, and the one recommended, is to wait until after the leaves have fallen in the autumn. The tents can then be removed by carefully cutting the branch to which it is attached. They can then be burned if you can do so safely and without causing nuisance to your neighbours. If you can’t burn them, they can be double bagged, sealed tightly and disposed of in the refuse bin.

Safety

If you decide to carry out a treatment yourself, you should:

• wear protective clothing (including goggles) that covers all bare skin
• follow the manufacturer’s instructions if spraying insecticide
• only spray insecticide when the weather is fine and there is no wind or rain
• ensure that a ladder is properly secured
• boil clothing after use as the irritant hairs will stick to it

If you are asthmatic, suffer from hay fever, have sensitive skin or suffer from eczema, you are strongly advised not to attempt to deal with an infestation yourself.