Lepidoptera Family Catocalida Moths

This family contains only four British species, but these few are very striking moths. They are of large size; and, unlike the Noctua generally, the chief adornment is reserved for the under wings. When at rest, the outer or fore wings completely hide the other pair, and then their general appearance is dull, though if closely examined it will be observed that these outer wings are really beautifully marbled with shades of grey.

The caterpillars of this family are very peculiar creatures. Their bodies are convex above and flattened beneath; and if disturbed as they rest on the bark of a tree, instead of leaving their hold and rolling into a ring like so many other larva of Noctua, they apply themselves the closer, and hold on as if to defy our attempts to remove them. Another peculiarity of these larva is the possession of fleshy projections along the sides, just above the legs. They feed on the leaves of trees, and when about to rest they descend to the trunk, and there remain protected by their imitative colouring, detection being rendered even more difficult by the close application of their flattened under surface to the bark. Before changing to the chrysalis state, they spin a light cocoon among the leaves or on the bark.