Invasion of Cutworm Moths Will Cause Economic Damage

Two cutworm moth species, recently introduced to British Columbia from Eurasia, are about to become economic pests throughout the province.

Large yellow underwing larvae feed voraciously on a smorgasbord of vegetation, ranging from grasses and cultivated flowers to agricultural crops and currant bushes.

The lesser yellow underwing devours various native BC herbs, with curled dock a favourite, and is also known to consume grapes.

After it was first found on Vancouver Island in 2002, the large yellow underwing Eurasian cutworm moth, Noctua pronuba, spread north to Sayward and east to the lower Fraser Valley. Since 1979 it has immigrated from Nova Scotia to all Canadian provinces and Nunavut. The moth is expected to colonized all of BC.

A close relative, the lesser yellow underwing, Noctua comes, was first discovered in Canada at Burnaby in 1982. It has since reached southern Vancouver Island, Lillooet and the Okanagan Valley.

Cutworm larvae hatch on the undersides of leaves, then begin feeding on foliage and roots. They typically overwinter in soil, emerging in spring as large moths sporting a orange-yellow hindwing with black markings.