E2023 (June 2021) Common Pests of Dry Beans Janet J. Knodel, Professor and Extension Entomologist Patrick Beauzay, State Integrated Pest Managment Coordinator and Research Specialist in North Dakota Veronica Calles-Torrez, Post-doctoral Scientist

Black Bean (Figure 1) Foliage Feeding Caterpillars Nymph: Similar to adult but smaller, black body with slight Green Cloverworm reddish tint, always without wings. Caterpillar or larva Adult: Small, about 1/16 inch (Figure 6): Mature long, pear-shaped, black body with larva about 1¼ inches white and black legs, two cornicles long. Pale green, with (look like tailpipes) at posterior one long narrow white end, winged or wingless. stripe on each side, Figure 1. Black bean . three pairs of fleshy Figure 6. Green cloverworm larva. Important vectors of viral diseases. (C. DiFonzo, Michigan State University) prolegs at the center (J. Gavloski, Manitoba Agriculture, Food and Rural part of the body and Initiatives) Grasshopper one pair of prolegs at the rear end. Moves in Nymph (Figure 2): Resembles the a looping behavior. adult, but smaller and without fully Adult (Figure 7): Wingspan developed wings (wing pads only). of 1 inch. Dark brown moth with spots. When moth rests, wings form a triangle. Figure 2. Grasshopper nymph. Migrates into North Dakota (P. Beauzay, NDSU) each spring. Adult (Figure 3): Size varies by Figure 7. Green cloverworm adult. species (1 to 1¾ inch long), brown to (J. Gavloski, Manitoba Agriculture, Food and Rural Initiatives) grayish-green, prominent head, large compound eyes, enlarged hind legs for jumping. Fully developed wings. Painted Lady Butterfly/Thistle Caterpillar Caterpillar or larva (Figure 8): Mature larva about 1½ Figure 3. Two-striped grasshopper adult. inches long. Brown to black with yellow striping along each (J. Knodel, NDSU) side of the body and covered with branched spiny hairs, giving a prickly appearance. Webbed nest in curled leaves Leafhopper where they feed on foliage. Black pellets (frass) inside web. Adult (Figure 9): Wing span of 2½ to 3½ inches. Forewings Nymph (Figure 4): Similar to adult, but smaller, greenish yellow red-orange and brown with black and white spots. Hindwings and wingless. orange-brown with four black “eye spots” along the edge. Adult (Figure 5): Less than c inch long, narrow, wedge-shaped, Feeds on flower nectar and aphid . Migrates into pale green body. Wings are translucent green and folded over the North Dakota each spring. back at rest. Nymphs and adults jump or walk rapidly sideways when disturbed. Migrates into North Dakota each spring.

Figure 4. Potato leafhopper nymph. Figure 5. Potato leafhopper adult. (J. Knodel, NDSU) (S. Brown, University of Georgia, Bugwood.org) Figure 8. Thistle caterpillar in Figure 9. Painted lady butterfly. webbed nest. (V. Calles-Torrez, NDSU) (P. Beauzay, NDSU) Armyworm Seed Corn Maggot Larva (Figure 10): Light tan to dark greenish-brown caterpillar Larva (Figure 14): with three longitudinal stripes (pale orange, white, brownish Maggot-like, about ¼ inch and/or black) on smooth and almost hairless body, about 1½ to long, cylindrical, legless, pale 2 inches long when mature. Defoliates leaves/pods, usually in yellow-white and sharply moist, shady areas where lodging is present. pointed at the head end with Adult (Figure 11): Light brown moth with a conspicuous white small black mouth hooks. Figure 14. Seed corn maggot larva. spot about the size of a pinhead on each front wing, wingspan of Found in hollowed-out seed, (W. Cranshaw, Colorado State University, 1½ inches. burrowing in emerging stem Bugwood.org) and cotyledon leaves. Larvae kill seedlings, preventing bean emergence (Figure 15). Adult (Figure 16): Grayish-brown fly, about ¼ inch long.

Figure 15. Damage to dry bean row from seed corn maggot. (J. Knodel, NDSU)

Figure 10. Armyworm Figure 11. Armyworm adult. (J. Fauske, NDSU) larva. (P. Beauzay, NDSU)

Cutworm Larva (Figure 12): Figure 16. Seed corn maggot adult. (Pest and Diseases Image Library, Black to pale gray Bugwood.org) body with markings (spots or stripes), about 1½ inches long Spider Mite when mature. Adult (Figure 13): Immature: Similar to adult, but smaller with six to eight legs. Dark gray, brown Figure 12. Dingy cutworm larva. or dull yellow or tan (J. Gavloski, Manitoba Agriculture, Food and Rural Initiatives) Adult (Figure 17): Very moths with dark wing small, less than 0.02 inch markings, robust body, (magnification is needed to see wingspan of 1¼ to 1½ them in detail), green, yellow Figure 17. Two-spotted spider mite. or orange body, two dark inches. (P. Beauzay, NDSU) spots on the abdomens for two-spotted spider mite, eight Figure 13. Dingy cutworm legs. Located on the underside adult. (G. Fauske, NDSU) of leaves. Produce spiderlike webbing (Figure 18) and stippling on leaves (Figure 19).

Figure 18. Webbing from two-spotted spider mites. (D. Cappaert, Michigan State University, Bugwood.org)

Figure 19. Stippling injury from two- spotted spider mites. (J. Knodel, NDSU)

Printing support was received from the Northarvest Bean Growers Association and the U.S. Department of Agriculture’s National Institute of Food and Agriculture, Crop Protection and Pest Management Program grant no. 2017-70006-27144

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