The Vapourer, Common vapourer, Orgyia antiqua
The vapourer, above, is widespread throughout Europe, and is also found in North America. It is found in woods, hedges, parks and gardens.
The eggs are brownish white, and are laid in July and August in a batch on the cocoon from which the female has just hatched. The eggs hatch the following spring, and the caterpillar feeds until July or August.
The caterpillar reaches 35 mm long when fully grown. The hairs can be irritating and cause a rash in some people. The caterpillar foodplant is almost any deciduous shrub. Pupation is in a cocoon on twigs or bark, and the cocoon is spun to incorporate the caterpillar hairs.
Adults emerge in July and August. The female is more or less wingless, and waits on her cocoon for a male to find and mate with her. She attracts the males by emitting a pheromone. The male flies by day. Male wing length is 14 - 16 mm.
Lymantriidae, Tussocks and Vapourers
The Lymantriidae are commonly known as the tussocks or vapourers. This comes from the tussocks of hairs seen in the caterpillars (see left). There are around 2700 species world wide.
The adults fly mainly at night, and are hairy and medium or large in size. The adult males have strongly feathered antennae, whereas the females have simple or just slightly feathered antennae. The males use their antennae as scent aerials to pick up molecules of the female pheromones sometimes from several km away, and fly down a chemical gradient in hope of a mate.
The tufts of hair on the hairy caterpillar are incorporated into the cocoons which are usually formed above ground. The hairs fall out easily when the caterpillar is handled and can cause irritation.