The glassy cutworm is most commonly associated with grasses and turf but may attack cereals, corn and vegetables, particularly if these crops are planted on newly broken sod or in crops infested with grassy weeds the previous fall. Larvae damage grass stands in the fall and following spring by feeding on stems and crown at or below the soil surface. Apparently, larvae sometimes pull severed leaf below the soil surface until it is entirely consumed. Commonly infested grasses are tall and creeping red fescues, timothy, bluegrass, and brome. Low, and even moderate, infestations may not cause noticeable damage if growing conditions are favourable.
Drought appears to be an important factor favouring population increases of glassy cutworm.
The severe outbreak in the Peace River Region in 2000 followed two years of drought. There is no established economic threshold for glassy cutworms in crops or pastures. Newly broken land and summer fallow with grassy weeds should be well cultivated during August to prevent new growth suitable for egg laying. Fields at risk should be monitored for evidence of browning-off or unusually poor growth during both the fall and early the next spring. Damaged or sickly plants should be dug up and the roots and surrounding soil searched for the presence of cutworms.