The "cats" (Catocala) are
among the most exciting of all the noctuids, whether as adults or as caterpillars.
Although the caterpillars are huge and spectacular, they are also one of the
most cryptic of all caterpillars and are extremely difficult to find as they
flatten themselves tightly along the length of a twig. I once had a full-grown
one sitting on a single, unbranched twig, and held it a few inches in front
of several colleagues, who were quite unable to see it. When discovered, however,
the caterpillar can jump! The pupa is covered with a delicate whitish bloom.
The moth emerges after just three or so weeks in the pupa, and is immediately
active - so much so that I had to photograph it immediately while it was still
perched in an aesthetically unpleasing place on a rearing cage. Although there
are some other moths (Archaearis, Peridroma, Noctua) that
are called "underwings", the unqualified name "underwing"
is generally understood to refer to this genus on account of the startling bright
colours (red in the majority of species) of the hind wings. The caterpillar
of C. aholibah feeds on oak.