Common Arthropod Pests of Corn in North Dakota

Larva (Figure 1): Slender, white to cream body with brownish head capsule and brown anal plate at the posterior end, about ½ inch long when mature. Feeds on roots. 

Adults: Northern corn rootworm (Figure 2): ¼ inch long, tan to pale green beetles. 

Western corn rootworm: 3/16 to 5/16 inch long. Yellow to yellowish green beetles with black markings on forewing. Most females (Figure 3) have three longitudinal black stripes on their forewings, and most males (Figure 4) have a nearly solid black marking

Larva (Figure 5): Black to pale gray, cylindrical-shaped body with markings (spots or stripes), about 1½ to 2 inches long when mature. Cut young plants below or above ground. 

Adult (Figure 6): Dark brown, black, drab gray, dull yellow or tan moths with wing markings, robust body, wingspan length of 1¼ to 1½ inches.

Larva (Figure 7): Pinkish gray or pale brown body marked with small brown dots in rows, brown head, about ¾ to 1 inch long when mature. Defoliate leaves and tunnel into stalks and corn ears/shanks. 

Adult (Figure 8): Straw-colored (pale yellow-brown) with brown wavy bands on wings, and 1 inch wingspread.

Nymph (Figure 9): Resembles the adults, but smaller without fully developed wings (wing pads only). 

Adult (Figure 10): About 1¾ inches long, brown to grayish green, prominent head, large compound eyes, enlarged hind legs for jumping. Fully developed wings. 

Grasshoppers feed on leaves, silks and ear tips.

Nymph: Similar to adult but smaller, always without wings. 

Adults: Small about 1/8 inch long, pear-shaped, pale to dark green, two cornicles (look like tail-pipes) at posterior end, winged or wingless. 

Both nymphs and adults feed on plant juices.

Larva (Figure 12): Maggotlike, about ¼ inch long, cylindrical, legless, pale yellow-white and sharply pointed at the head end with small black mouth hooks. Burrow into seeds, emerging stems and cotyledon leaves. 

Adult (Figure 13): Grayish brown fly about ¼ inch long.

Immature: Similar to adult, but smaller with six to eight legs. 

Adult (Figure 14): Very small, less than 0.02 inch (magnification is needed to see them in detail), green, yellow or orange body, two dark spots on the abdomen for two-spotted spider mite, eight legs. Located on the underside of leaves. Produce spiderlike webbing (Figure 15) and stippling injury on leaves (Figure 16).

Larva (white grub, Figure 17): White to cream body with brown head, three pairs of legs, C-shaped, about 1½ inches long when mature. Feeds on roots in soil. 

Adult (Figure 18): Brown to reddish-brown beetles, about ¾ inch long.

Published with supported from the North Dakota Corn Council and the USDA National Institute of Food and Agriculture, Hatch Project Accession No. 1024297 and the Crop Protection and Pest Management Program [grant no. 2017-70006-27144].