depending on the time of year. During the late fall and early winter, a dormant oil stray can be used to suffocate the eggs. When the eggs are newly hatched in late March and early April Bt (Bacillus thuringiensis) is a safe and effective way to control caterpillars. As the caterpillars get bigger, spinosad is also effective. References Further reading Chinery, Michael, Collins Guide to the Insects of Britain and Western Europe, 1986 (Reprinted 1991) Skinner, Bernard, Colour Identification Guide to Moths of the British Isles, 1984 External links UKmoths Winter Moth Operophtera brumata (Linnaeus, 1758) Lepiforum.de many excellent photos Operophtera Agricultural pest insects Insect pests of temperate forests Moths described in 1758 Moths of Europe Moths of Iceland Moths of North America Moths of Asia Taxa named by Carl Linnaeus