corn earworm moth

not listed

NNR - Unranked

SNR - Unranked

not listed

Corn earworm moth is a medium-sized, late season, flower moth. It occurs across the United States and southern Canada, in Mexico, in Central America, and in South America. It is common in Minnesota. Larvae feed on a wide variety of herbaceous plants. It is a major pest of many agricultural crops, including corn, tomatoes, and cotton. Other common names for it are tomato fruitworm and cotton bollworm. Adults do not survive northern winters. They migrate north every year, first appearing in Minnesota in late July or in August, depending on the severity of the preceding winter. They are found in croplands, old fields, and other open disturbed areas.

Adults are 11⁄16″ to ⅞″ (18 to 22 mm) in length and have a 1¼″to 1¾″ (32 to 45 mm) wingspan. Moth size is often given in terms of forewing length, which in this case is ⅝″ to ¾″ (16 to 20 mm).

The forewing of the female is yellowish-brown to orangish-brown and mottled with gray to reddish-brown. The terminal area is lighter and the subterminal area is usually darker. The lines are light gray, orangish-brown, or the same color as the background but darker. On some individuals they are faint and barely perceptible. The basal and antemedial (AM) lines are scalloped with the scallops pointed rearward. The AM line has dots at the bases of the scallops. The median line is wavy. The postmedial (PM) and subterminal lines are scalloped with the scallops pointing forward. There is a dark dot, often with a smaller white spot, at the base of each scallop. The terminal line is represented as a row of small dots between the veins. The orbicular spot is round and the same color as the wing background but with a dark spot in the center and a thin faint outline. The reniform spot is similar but kidney-shaped and with a dark blotch in the center. The fringe is darker than the terminal area.

The hindwing is pale brownish-white with dark gray veins; a dark, bar-like discal spot; a broad dark terminal band; and a white fringe. The terminal band has two pale spots near the outer margin.

The male is similar but lighter and with a green to olive cast.

The caterpillar is up to 19⁄16″ (4 cm) long and is highly variable in color. It may be pale tan, yellow, orange, red, maroon, green, dark brown, or nearly black. The body is covered with minute black spines, but these are visible only under magnification. Longitudinal stripes on the body may be well-defined, diffuse, or faint. There is a thin dark stripe in the middle (middorsal), a dark stripe on each side above the breathing pores (spiracles) and a pale stripe below the spiracles. On the first segment of the thorax there is a pair of stiff hairs (setae). Unlike most noctuid moth caterpillars, these setae are aligned horizontally, parallel to the body axis.

Total length: 11⁄16″ to ⅞″ (18 to 22 mm)

Wingspan: 1¼″to 1¾″ (32 to 45 mm)

Forewing length: ⅝″ to ¾″ (16 to 20 mm)

Croplands, old fields, open disturbed areas

Several generations per year: Late July through September

Adults are active at night and will come to lights.

A wide variety of herbaceous plants

Flower nectar

Sources

4, 21, 22, 29, 30, 71, 75, 82, 83.

On my sunflower!

Here's another one from the garden earlier.

Helicoverpa zea corn earworm moth

… on New England aster.

Location: Silver Bay, MN

On my sunflower!

Location: Silver Bay, MN

Here's another one from the garden earlier.

Location: Barnes Prairie, Racine Co., WI

… on New England aster.