Venusia cambrica, the Welsh wave, is a moth of the Geometridae family. It is found in Europe, western and central Siberia, Altai, Transbaikalia, the Russian Far East, the Korean Peninsula, Japan and in North America, where it can be found across Canada from Newfoundland and Labrador to British Columbia, south in the west to California, south in the east to Georgia. Adults are on wing from July to August in western Europe, from June to September in New Brunswick and Quebec and from March to August in California. There are two generations per year.