Phylum: Arthropoda; Class: Hexapoda (Insecta); Order: Lepidoptera; Family: Noctuidae; Genus: Agrotis

Different species of cutworm are found worldwide.

Larvae

Larvae (caterpillars) plump, smooth caterpillars, greasy in appearance and can range in colour from grey to brown or black depending on the species.  They may be up to 40mm long. Larvae generally have two spotted yellow stripes running down the back. The larvae curl into a C shape (grub-like or scarabaeiform ) when disturbed and remain motionless for a short period. They commonly hide just under the soil or litter by day or may be found on the soil surface adjacent to severed vegetation.

Adults

Adults are dark grey, black or brown coloured moths with markings on the front wings, which vary according to species. They have a wingspan of 40-50mm and are 20-30mm long.  Females are darker than males but otherwise similar.

Adult moths are nocturnal and lay eggs on vegetation, on moist ground around plants, or in cracks in the ground. Egg laying begins 5-11 days after emergence. The larvae hatch after 3 (at +29-30°C) to 24 days (at +10-12°C), and the young cutworms feed on vegetation near the ground.  After 10-14 days they avoid daylight and become nocturnal feeders, remaining in the soil during the daylight hours. Larvae develop in 24-40 (sometimes 90-100) days, reaching 40-52 mm in length at the last 6th instar, depending on available food.  When fully fed, the cutworms rest in the soil for about a week before pupating about 40 mm below soil level. The pupae stage lasts two to three weeks but may take up to two months depending on temperature. Depending on the species and latitude, one to three or four generations may occur in a year.

Larva (caterpillar ) feeding on plants

Cutworms are indiscriminate feeders, causing damage to a variety of crops, mainly when these are young.  Among the crops that commonly suffer are maize, tobacco, potatoes, young coffee, cotton,  asparagus, bean, beet, cabbage, castor bean, grape, lettuce, onions, cabbages, peanut, pepper, potato, radish, spinach, squash, strawberry, rice, rye and tomato.

Seedlings and young plants.

Stems, leaves in very young plants

Cutworms usually feed at night or during overcast days. Newly hatched larvae feed on weeds, and/or young maize plants if present, leaving small irregular holes in the leaves. Such early feeding is of little significance to plants.

Larger larvae may completely cut through stalks, which can cause plants to wilt and die. Severe stand reductions can result. They sometimes drag cut plants under soil clods or into small holes in the soil to continue their feeding during the daylight hours.

In other crops like potatoes and root vegetables, damage can take the form of unsightly holes in the subterranean tubers, which may allow the penetration of secondary fungi.