Abstract:
The bertha armyworm, Mamestra confi gurata
Walker, belongs to the order Lepidoptera
and family Noctuidae. It often is referred to
as the “Miller Moth” or “climbing cutworm.” Its
geographical range extends as far south as Mexico
City, Mexico, and as far north as Keg River, Alberta,
Canada. It is native to North America and is an
important insect pest of canola in the northern Great
Plains. In North Dakota, bertha armyworm occurs
primarily throughout the northern canola-producing
counties. Severe infestations of bertha armyworm can
be sporadic or widespread and usually occur every
fi ve to seven years. However, in years when outbreaks have occurred, larval feeding has caused economic
crop losses and increased production costs from
spraying insecticides
