Moths in the Zygaenidae family - Burnet moths, and Lymantriidae

Zygaenidae family, Burnet and Forester moths

Moths in the Zygaenidae family are commonly known as the Burnet moths and forester moths. The adults are day fliers, and although their antennae are clubbed they are still considered moths, not butterflies. The adults and larvae are warningly coloured to avoid predation. They sequester poisons such as cyanide.

There are around 800 species in the family worldwide, and 10 in the U. K. They often live in colonies isolated from others of the same species, consequently there are many races or sub-species.

Zygaena filipendulae, the Six-spot Burnet

This moth (left) is widespread and fairly common, in fact it is probably the most common Burnet in the U. K. It is also common in Europe. There is one generation a year in the U. K. It is found in flowery grassland, roadside verges, pasture and coastal grassland.

Eggs are laid on birdsfoot trefoil in July or August.

Caterpillar length is up to 22 mm long. The body shape is short, fat and tapering at both ends (a bit like me really). The foodplant is birdsfoot trefoil. On hatching the caterpillars feed, then hibernate through the winter. They emerge in the spring and feed again.

Pupation takes place attached to grass stems.

Adults emerge in June or July. And fly on sunny days in open grassy sites with plenty of flowers until August. They have protective red and black colouring warning predators that they are not good to eat. In fact they can exude a fluid containing cyanide if attacked. The front wing length is 15 - 19 mm. During the flight season males patrol looking for unmated females. The sorry-looking adult on the left was found on a day after heavy rain showers.

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. 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.