Why is it important to control brown tail moths?

Brown Tail Moth caterpillars have small hairs all over their bodies, which can break off very easily and irritate the skin, in some cases very severely.  Some people can also suffer a type of asthmatic reaction.

Minor skin irritations should be washed immediately with hot soapy water and calamine lotion applied if necessary.  If you have serious persistent symptoms, for example the hairs go in your eyes or are inhaled you should see a doctor.

They can also be a garden pest, quickly stripping trees and shrubs of foliage.

How can you identify a brown tail moth?

Caterpillars

About 1" long with two red spots on its back.  Covered with brown hair which is responsible for skin irritation.

Moths

White winged with a brown body.  The female has a bushy brown hair tail (hence the name).  These moths are nocturnal.

Life Cycle

In order to identify these moths accurately it is important to know the different stages of the insect throughout the year:

  • Mid July - At this time of year the moths mate, laying eggs covered in small brown hairs on the underside of leaves and bushes.  These bushes most commonly are of the Hawthorn, Blackthorn or related fruit bush variety, although it can include a wide variety of other trees.
  • Late Summer - In August/September time eggs hatch and feed on foliage, turning the leaves a brown 'scorched' colour.
  • Winter - Caterpillars weave a web like structure in the bush or tree which they use to hibernate.
  • Late Spring - Caterpillars emerge from their hibernation to feed on the surrounding foliage
  • Late June - Caterpillars turn into black chrysalides.
  • Mid July - Chrysalides hatches into adult moth (described above).

Brown Tail Moth Caterpillar Brown Tail Moth Caterpillar Hibernation Brown Tail Moth

Prevention and treatment

Depending on the time of year and the stage of development at which the moth is at there are two main methods of eliminating the pest:

  • Winter (November to March) - During the winter the caterpillars can be destroyed whilst they are in hibernation in their webs.  These webs can be completely cut out of trees and bushes, eliminating between 300-400 caterpillars per web, and burnt in a responsible manner.
  • Summer (May to September) - Another way of getting rid of these moths is to spray the bushes and trees affected, again, eliminating the moth at the caterpillar stage.  Pesticides available for this type of treatment are available and can be bought from either pet shops or various DIY superstores.