Chestnut Conistra vaccinii
Specialists do not identify the Chestnut by looking at its color. Nor do they study the markings on the wing, for both are extremely variable. They look at the shape. The Chestnut has a rather unique shape of the front wing. The rear edge is very rounded and the wing runs inwards much more than it does in other Owlet moths. The color of the wing is extremely variable: it may be deep reddish brown like a chestnut, dark brown or even almost black. Some animals are well marked. These have a well defined kidney spot and the circular spot is easy to see as well. In each of these spots sits a black dot. Others are less well marked. There is no trace of the kidney and circular spots, bit the black dots may be still there, or just one. Many others have no dots at all, but are strongle marbled. This is especially true of darker animals, like the one in the pictures on this page. Still it is sometimes very hard to see the marbled markings. Most dark Owlet moths landing on your doorstep from December to February are Chestnuts. In other months there are lots of similar species flying about and you will need to look at the shape of the wing. The Chestnut is not a big moth, for the wingspan is only some 28 to 36mm.
Even though the animals start flying in September, the eggs are laid next spring. They are deposited in all kinds of trees or shrubs. Usually the eggs are laid one by one, but occassionally small heaps of eggs are found. They hatch after two weeks. The small caterpillars eat from the fast growing leaves of the foodplant. Some always stay in the tree or shrub where they were born. Most drop to the undergrow during the 3rd instar to complete their development on low growing plants such as blueberry or dock. By the end of June the caterpillar goes underground where it spins a relatively large cocoon. They rest inside the cocoon for about two months before pupating. The first moths will leave the cocoon in September. It is the adult moth overwintering. The caterpillar of the Chestnut is just as variable as the adult moths are. It maybe darkbrown, purplish brown, light brown or even ochreous. It may also be almost black. But some are greenish, greyish or even greyish green. All however have small white speckles. And all have three more or less visible white dorsal lines. Characteristic is the neck shield: it is brownish black with three white lines. The head is brown with lightbrown dots. The caterpillar reaches a length of 30 to 35mm.
The Chestnut is on the wing in two stages. First from September to the end of November. Then follows a winter break, although some specimens can be seen on mild winterdays. Varying with the weather the Chestnut becomes active again by the end of February or the beginning of March. They remain on the wing til mid-May usually. The eggs are being laid from March. The Chestnut flies by night exclusively. It is attracted to light in very small numbers only, but responds well to sugar. In autumn the animals live on the nectar found in ivy blossom and they suck on rotting fruit and berries. In spring they are mainly seen on catkins. If you catch an animal at night, it is easily photographed during the day, but most won't be handled. A common and often even abundant species in England and Wales. Common, but less frequently seen in Scotland and Ireland. Common to abundant on the European continent too.