About Besma quercivoraria (Guenée, 1857)
Besma quercivoraria, commonly known as the oak besma, is a moth species belonging to the family Geometridae. It was first formally described by Achille Guenée in 1857. This species can be found across southern Canada, spanning from Newfoundland to British Columbia, as well as throughout almost all of the United States, with the exception of California. Adult oak besma moths display sexual dimorphism, and their wingspan measures between 27 and 41 mm. Adult moths are active in flight from April to September in the southern part of their range, from May to August in Ontario, and from late May to July in Alberta. This species produces two generations each year. The caterpillar larvae feed on the leaves of oak, elm, poplar, and willow, in addition to Picea glauca. In southern Canada, larvae feed primarily on leaves of Betula papyrifera.
