Doubtfully present in:
Italy
Native to:
Alabama,
Alaska,
Alberta,
Aleutian Is.,
Altay,
Amur,
Argentina Northwest,
Argentina South,
Arizona,
Arkansas,
Austria,
Baltic States,
Belarus,
British Columbia,
Buryatiya,
California,
Central European Russia,
Chile Central,
Chile South,
China North-Central,
China South-Central,
Colorado,
Connecticut,
Czechoslovakia,
Delaware,
District of Columbia,
East European Russia,
Finland,
France,
Georgia,
Germany,
Great Britain,
Greenland,
Idaho,
Illinois,
Indiana,
Inner Mongolia,
Iowa,
Irkutsk,
Japan,
Kamchatka,
Kansas,
Kazakhstan,
Kentucky,
Khabarovsk,
Kirgizstan,
Korea,
Krasnoyarsk,
Kuril Is.,
Magadan,
Maine,
Manchuria,
Maryland,
Massachusetts,
Mexico Central,
Mexico Gulf,
Mexico Northeast,
Mexico Northwest,
Mexico Southwest,
Michigan,
Minnesota,
Mississippi,
Missouri,
Mongolia,
Montana,
Nepal,
Nevada,
New Brunswick,
New Hampshire,
New Jersey,
New Mexico,
New York,
North Carolina,
North Caucasus,
North Dakota,
North European Russia,
Northwest European Russia,
Northwest Territories,
Norway,
Ohio,
Oklahoma,
Ontario,
Oregon,
Pakistan,
Pennsylvania,
Poland,
Primorye,
Qinghai,
Québec,
Rhode I.,
Romania,
Sakhalin,
South Dakota,
South European Russia,
Svalbard,
Sweden,
Switzerland,
Tennessee,
Texas,
Transcaucasus,
Turkey,
Tuva,
Ukraine,
Utah,
Vermont,
Virginia,
Washington,
West Himalaya,
West Siberia,
West Virginia,
Wisconsin,
Wyoming,
Xinjiang,
Yakutskiya,
Yugoslavia,
Yukon
Introduced into:
Belgium,
Denmark,
Iceland,
Netherlands