Primarily the black cutworm, Agrotis ipsilon; glassy cutworm, Crymodes devastator; and the variegated cutworm Peridroma saucia
Time of concern: Seedling stage
Key characteristics: Mature larvae, 1 1/4 to 1 3/4 inches in length, may appear "greasy." Larvae curl into a C when disturbed. Young plants with small holes in the leaves, wilted leaf tips, or lodged plants are indicative of cutworms.
Scouting should begin soon after plant emergence and be repeated twice per week until plants are established. Focus sampling on field edges that border natural vegetation and weedy or poorly drained areas. If cutworm damage is suspected, confirm presence of larvae by screening the soil under and around injured plants. No thresholds have been established.
Naturally-occurring predators, parasitoids, and pathogens help suppress infestations. Use Natural Enemies of Vegetable Insect Pests for identification of natural enemies.
|Note(s)||Cutworm larvae should be controlled when small, and because of their nocturnal behavior, treatments should be applied late in the day. Also, because damage will be somewhat limited to field edges or low areas in the field, only the infested (damaged) areas and a buffer area of 20 to 40 feet around the damage may need to be treated.|
|Resistant varieties||No resistant varieties are available.|
|Crop rotation||If possible, avoid fields with a history of cutworm problems.|
|Site selection||If the land has a history of cutworm injury, be prepared to treat before the worms are 1/2 inch long. The moths are attracted to weeds. Avoid fields containing weeds, especially winter annuals.|
|Insecticide Resistance Management||
The Insecticide Resistance Action Committee (IRAC) has classified insecticides into resistance management groups. Most insecticides include an IRAC group number on the front page of the label. Alternating between insecticides with different group numbers will help avoid the development of resistant insect populations.
|These are not currently viable management options.|
|Pesticides||Cornell Integrated Crop and Pest Management Guidelines for Commercial Vegetable Production|