Okra has few noticeable pests. Pods that are curled or have wartlike protrusions commonly indicate feeding damage by stink bugs or leaffooted bugs. Corn earworms (also known as tomato fruitworms) also infest pods occasionally. Japanese beetles may eat the foliage, though damage is usually negligible unless populations are unusually high.

A. Insects that feed externally on buds, foliage, or pods

Chewing insects that leave holes in plants
1. Corn earworm (also known as tomato fruitworm)—Early instars are cream colored or yellowish green with few markings; later instars are green, reddish, or brown with pale, longitudinal stripes and scattered black spots. They are moderately hairy, up to 1 3/4 inches long, and have three pairs of legs and five pairs of prolegs (Figure 1). They eat holes in pods (Figure 2). (For more information about corn earworms, see "Pests of Sweet Corn.")
2. Yellowstriped armyworm—This smooth, dark-gray to black caterpillar has a distinct yellow stripe on each side and a pair of black triangles on the back of most segments. It grows up to 1 3/4 inches long. It feeds on leaves, tender stems, and pods (Figure 3). (For more information about yellowstriped armyworms, see "Pests of Sweetpotato.")
3. Japanese beetle—This hard-bodied, shiny, metallic-green beetle has coppery-brown wing covers that meet in a straight line down the center of the back. Its body is about 1/2 inch long (Figure 4). It skeletonizes leaves and may also eat pods.
Pests that cause discoloration or distortion of plant
1. Aphids—These soft-bodied, pear-shaped insects have a pair of dark cornicles and a short tail (called the cauda) protruding from the abdomen. They may be winged or wingless; the wingless forms are most common. They feed in colonies and excrete honeydew on which sooty mold grows.
  1. Green peach aphid—The yellow to green to pink wingless adult is almost 1/8inch long (Figure 5A). The winged adult (Figure 5B) has a dark dorsal blotch on a yellowish-green abdomen. The cornicles are more than twice as long as the cauda. Nymphs may have three dark lines on the abdomen (Figure 5C). (For more information about green peach aphids, see "Pests of Lettuce.")
  2. Melon aphid—This aphid is yellow or green in hot, dry summers and pale green to dark green in cool seasons. Its body is a little more than 1/16 inch long, with cornicles slightly longer than or twice as long as the cauda (Figure 6A). Winged forms (Figure 6B) are darker. The nymph (Figure 6C) is similar in color to the adult. (For more information about melon aphids, see "Pests of Cucurbits.")
2. Stink bugs and leaffooted bugs—These bugs may be up to 3/4 inch long. Adult stink bugs are green or brown and shield-shaped (Figure 7A). Leaffooted bugs are brown with wide, flat legs (Figure 7B). Stink bug nymphs (Figure 7C) are pale-green or green with orange-and-black markings. Leaffooted bug nymphs (Figure 7D) are red. These bugs pierce buds, pods, and seeds, causing pods to be deformed and seeds to be shriveled; wartlike growths appear on pods.

B. Insects that feed inside the stalk or leaf

European corn borer—This pale-yellow or pinkish caterpillar is up to 1 inch long with several rows of tiny, dark-colored spots. It has three pairs of legs near the head and five pairs of prolegs (Figure 8). It leaves an entrance hole in the stalk fringed with frass held together by silk it secretes (Figure 9). The borer weakens the stem and interferes with pod development. (For more information about European corn borers, see "Pests of Sweet Corn.")
Vegetable leafminer—This colorless to bright-yellow maggot has black mouthparts, with a body up to 1/8 inch long and a pointed head (Figure 10). It makes S-shaped mines in leaves, often enlarged at one end. (For more information about vegetable leafminers, see "Pests of Tomato.")

Side view of caterpillar’s extended body, showing legs and prolegs, line down side, and delicate hairs protruding from body. Black and white art.

Figure 1. Corn earworm.

Illustration by Susan Van Gieson.

ALT TEXT: Yellowish caterpillar with brown spots boring a hole near tip of okra pod. Head is buried in pod, with the rest of the lower body is exposed.

Figure 2. Corn earworm boring into okra pod.

Photo by J.R. Baker, NC State.

Caterpillar crawling on okra stem just beneath pod. Yellow longitudinal stripe and black spots visible on insect.

Figure 3. Yellowstriped armyworm on okra.

Photo by J.R. Baker, NC State.

Top view of dark beetle with ridged, leathery wing covers folded over back, six legs, and two club-shaped antennae. Black and white art.

Figure 4. Japanese beetle.

Illustration by Ponglerd Kooaroon.

Top view of oval-bodied nymph with 6 legs and 2 antennae. Two cornicles on either side of cauda at bottom tip of body. No wings. Black and white art.

Figure 5A. Green peach aphid—wingless adult. Illustration by USDA.

Top view of stubby-bodied aphid with clear, thin wings spread. Black-and-white art.

Figure 5B. Green peach aphid—winged adult.

Illustration by USDA.

Top view of oval-bodied nymph showing six legs and two antennae. Wing buds present. Black and white art.

Figure 5C. Green peach aphid nymph with wing buds.

Illustration by USDA.

Top view of oval-bodied insect showing six legs and two antennae. No wings present. Black and white art.

Figure 6A. Melon aphid—wingless adult.

Illustration by USDA.

Top view shows two long hind legs, two front legs, two antennae, and clear, thin wings spread. Two cornicles on either side of cauda at bottom tip of body.

Figure 6B. Melon aphid—winged adult.

Illustration by USDA.

Top view of oval-bodied nymph with 6 legs and 2 antennae. Two cornicles on either side of cauda at bottom tip of body. No wings. Black and white line art.

Figure 6C. Melon aphid nymph.

Illustration by USDA.

Top view of shield-shaped insect showing six legs, two antennae, and small head. Leathery wings folded back over body. Black-and-white line art.

Figure 7A. Adult stink bug.

Illustration by Mei-Jung Lin and L.L. Deitz.

Top view of slender-bodied, dark insect with horizontal white line visible across folded wings. The two bowed back legs are wide and flat. Black and white art.

Figure 7B. Leaffooted bug.

Illustration by USDA.

Top view of nymph showing wide, rounded body. Less shield-shaped than adult, with thicker legs and antennae and more prominent, beady eyes. Black and white art.

Figure 7C. Stink bug nymph.

Illustration by USDA.

Top view. Spikes around lower body, flattened back legs, and extended tubelike mouthparts with long antennae on either side. Black band across thorax.

Figure 7D. Leaffooted bug nymph.

Illustration by USDA.

Side view of caterpillar’s tubular body, showing legs and prolegs, dark head, and delicate bristles on body. Tapered at rear. Black and white art.

Figure 8. European corn borer.

Illustration by J.R. Baker, NC State.

Close-up of light-green weed stems with elongated dark recess in one. Bottom half of hole is filled with fluffy mass of brownish excrement and silk.

Figure 9. Damage to weed made by European corn borer.

Photo by J.R. Baker, NC State.

Side view of lightly C-shaped, tubular body of maggot, tapered at both ends. Black and white line art.

Figure 10. Vegetable leafminer.

Illustration by J.R. Baker, NC State.

Japanese Beetle

Popillia japonica Newman, Scarabaeidae, COLEOPTERA

Description

Adult—About 1/2 inch long, this shiny, metallic-green beetle has coppery-brown wing covers that extend almost to the tip of the abdomen (Figure 11A). Two small tufts of white hairs occur just behind the wing covers on each side of the body. Five more white patches are located on each side of the abdomen.

Egg—The white or cream-colored egg is spherical and about 1/16 inch in diameter when first laid in turf. By the time it hatches, the egg has doubled in size.

Larva—The grayish-white, slightly curled grub has a yellowish-brown head and is about 1 inch long when mature (Figure 11B and Figure 12). It can be distinguished from other white grubs by two rows of spines that form a tiny V on the underside of its last abdominal segment (Figure 11C).

Pupa—The cream-colored pupa, about 1/2 inch long and 1/4 inch wide, gradually turns light brown and finally develops a metallic-green cast.

Biology

Distribution—First reported in North America in 1916, the Japanese beetle now occurs in more than 20 states from southern Maine southward into Georgia and westward into Kentucky, Illinois, Michigan, and Missouri. It occurs statewide in North Carolina, with heaviest infestations in the mountains and central piedmont.

Host Plants—Adult Japanese beetles infest more than 275 plant species, including most vegetable garden and field crops. They also damage shade and fruit trees, ornamental shrubs, small fruits, and weeds. The grubs are serious pests of lawns, other grasses, and nursery stock.

Damage—Gregarious in nature, Japanese beetle adults are often found feeding in masses on flowers, foliage, or fruit of a few plants, leaving others nearby alone. On most hosts, including okra, leaves are skeletonized, and mature fruit is damaged.

Life History—The grubs overwinter in cells within 5 inches of the soil surface. In spring, they move upward, almost to ground level, where they complete feeding and pupate. The three larval instars complete development in about 140 days. Adults emerge as early as mid-May in eastern North Carolina and as late as July in New England. Throughout summer, they attack the fruit and foliage of many plants, including silks of corn. In North Carolina, peak emergence occurs in July. Soon after emerging, females deposit 40 to 60 eggs in small batches 2 to 3 inches deep in the ground. Under extremely dry conditions, many eggs and larvae perish. During warm, wet summers, however, populations thrive, and eggs hatch about two weeks after deposition. Newly emerged larvae feed until cold weather forces them into hibernation. Only one generation occurs each year.

Control

Milky spore disease and several parasites often attack beetle grubs and thereby keep Japanese beetle adult populations below economically damaging thresholds. Control of this pest is rarely necessary on okra or on vegetable crops that are sprayed regularly for control of other insect pests. Some plants in border rows may appear heavily infested due to the tendency of these beetles to congregate as they feed. If excessive populations develop, follow recommendations in the North Carolina Agricultural Chemicals Manual.

Figure 11A. Japanese beetle adult.

Illustration by Ponglerd Kooaroon.

Side view of curled, light-colored grub with dark head and three legs behind it. Small, black dots on outer edges of body segments. Black and white art.

Figure 11B. Japanese beetle larva.

Illustration by J.R. Baker, NC State.

Close-up of last abdominal segment showing fine detail of many fine hairs and some coarser hairs. Black and white art.

Figure 11C. The arrangement of microscopic hairlike structures (setae) on the lower tip of the abdomen is unique to Japanese beetle larvae.

Illustration by Susan Van Gieson.

Curled, plump, whitish-yellow grub lying on its side on top of soil. Shows dark-yellow, small head.

Figure 12. Japanese beetle grub.

Photo by Haruo Tashiro, Cornell University.