Lepidoptera The Goat Moth – Cossus Ligniperda
There are only three British species of this family, the largest of which is the Goat Moth, so called on account of the characteristic odour of the larva, an odour said to resemble that emitted by the goat.
The fore wings of this fine moth are pale brown, clouded with white, and marked by numerous wavy transverse lines. The hind wings are somewhat similar, but of a duller tint, and the markings are less distinct. Its average breadth from tip to tip is over three inches, and it sometimes reaches nearly four inches.
The larva is a most interesting creature. It is dark reddish brown on the back, and flesh colour beneath; and its head is intensely black. It feeds on the solid wood of the willow, poplar, oak, elm, and other trees. The infected trees are often so riddled with the burrows of these larva that they are completely destroyed, and the presence of the intruders is frequently indicated by a heap of small chips of wood lying on the ground near the roots. The odour of the larva, too, is so powerful, that there is generally no difficulty in ascertaining their whereabouts by it alone.
It is not always in living trees, however, that we find these creatures, for they often feed on rotting wood, such as the remains of old palings and posts, that lie on the ground in damp places.
When fully grown they construct a strong cocoon of chips of wood, bound together by silk, and within this they change to the chrysalis.
The moth emerges in June or July, and is commonly found resting on the bark of willows and poplars during the daytime.