''Besma quercivoraria'', the oak besma, is a

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

of the family

Geometridae The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek ''geo'' γεω (derivative form of or "the earth"), and ''metro ...

. The species was first described by

Achille Guenée Achille Guenée (sometimes M.A. Guenée; 1 January 1809 – 30 December 1880) was a French lawyer and entomologist. Biography Achille Guenée was born in Chartres and died in Châteaudun. He was educated in Chartres, where he showed a very earl ...

in 1857. It is found across southern

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

(from Newfoundland to

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, ...

) and all of the United States except

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

. Adults are sexually dimorphic. The

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan o ...

is 27–41 mm. Adults are on wing from April to September in the south, from May to August in Ontario and from late May to July in Alberta. There are two generations per year. The larvae feed on the leaves of oak, elm, poplar, willow, ''

Picea glauca ''Picea glauca'', the white spruce, is a species of spruce native to the northern temperate and boreal forests in North America. ''Picea glauca'' is native from central Alaska all through the east, across southern/central Canada to the Avalon Pe ...

'', and mostly ''

Betula papyrifera ''Betula papyrifera'' (paper birch, also known as (American) white birch and canoe birch) is a short-lived species of birch native to northern North America. Paper birch is named for the tree's thin white bark, which often peels in paper like ...

'' in southern Canada.

External links

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''Moths of North Dakota''
Ourapterygini {{Ourapterygini-stub