Peppers

Green peach aphid adult (winged form).

Identification tip:

The winged form has a distinct dark patch near the tip of the abdomen; wingless forms lack this dark patch. Sticky traps give an indication of movement into a field.

Thrips adult.

Identification tip:

The adult is tiny (less than 1/16 inch), pale yellow to light brown, and has two pairs of wings fringed with long hairs. Yellow sticky traps used to monitor for aphids, psyllids, and whiteflies can also be used to monitor for thrips.

Tomato (potato) psyllid adult.

Identification tip:

The adult is about 1/8 inch long and resembles a cicada. It has clear wings, white or yellowish markings on the thorax, and lines on the abdomen. Place sticky traps at field margins near tops of plants as an indicator of psyllid movement.

Whitefly adult.

Identification tip:

Tiny (roughly 1/16 inch long), yellowish insects with white wings. Sticky traps may be useful in detecting initial migrations into the field.

Cutworm damage.

Identification tip:

Larval feeding can cut off seedling leaves (right).

Beet armyworm damage.

Identification tip:

Young beet armyworms skeletonize leaves and produce webbing and frass. Older larvae chew holes in foliage and fruit.

Broad mite damage.

Identification tip:

Feeding causes leaf elongation, a wrinkled surface and downward curling. Inspect such leaves with a hand lens to look for the mite.

Flea beetle damage.

Identification tip:

Adult flea beetles feed on the undersides of leaves creating small pits or irregularly shaped holes.

Green peach aphid damage.

Identification tip:

Generally pale green although some individuals are pinkish. There are both winged and wingless forms.

Ground beetle damage.

Identification tip:

Ground beetle feeding eventually girdles the stem causing the plant to collapse and die.

Leafminer damage.

Identification tip:

Larvae mine between upper and lower leaf surfaces, creating winding, whitish tunnels that widen as the larva grows. Eventually this leads to necrosis.

Omnivorous leafroller damage.

Identification tip:

Larvae fold leaves and feed inside.  Look for chewed holes and webbing.

Pepper weevil

Identification tip: The adult weevil is about 1/8 inch long and dark bodied with a brassy luster. Pepper weevil is found in Southern California. Start monitoring after planting. Pepper weevil becomes more of a concern starting at bloom.

Seedcorn maggots.

Identification tip:

Where slow, spotty emergence is observed, dig up the seed and inspect for larvae. They are about 1/4 inch, whitish, cylindrical and taper toward the end (rare in older plants).

Thrips damage.

Identification tip:

Thrips feeding distorts foliage and can cause leaves to curl and pucker.

Tomato fruitworm.

Identification tip:

Newly hatched larvae have black heads and are creamy white with black spots and hairs. More mature larvae (shown here) range from yellowish green to nearly black, have fine white lines along the body and retain the black spots with hairs.

Tomato (potato) psyllid damage.

Identification tip:

As psyllids feed on leaves, they deposit honeydew in the form of sugar crystals.

Twospotted spider mite damage.

Identification tip:

Feeding can cause leaves to yellow and eventually die. Twospotted spider mites produce webbing on plants where they feed.

Wireworm larva damage.

Identification tip:

Wireworm feeding stunts a seedling, eventually killing it. Young plants are most susceptible (rare in older plants).

Whitefly damage.

Identification tip:

Feeding on leaves produces honeydew and "frost" on surface.

Identification of silverleaf whitefly is important. Other whitefly species do not cause economic damage in pepper.

Yellowstriped armyworm damage.

Identification tip:

Armyworms chew holes in leaves. They are usually black with one prominent stripe over many narrow bright ones on each side of their body.

Alfalfa mosaic virus symptoms.

Identification tip:

Leaves of infected plants have distinct yellow or whitish mosaic patterns.

Bacterial spot symptoms .

Identification tip:

Spots are about 1/4 inch in diameter, initially water soaked, and later turn brown.

Botrytis gray mold.

Identification tip:

Appears as gray-brown velvety covering on leaves or stems. Symptoms sometimes appear at the seedling stage, but are more likely at later stages.

Cucumovirus mosaic diseases.

Identification tip:

Generally, plants show an overall lighter color with mosaic patterns, stunting, leaf curling, and oak leaf patterns (shown here).

Curly top symptoms.

Identification tip:

Internodes of infected plants shorten, resulting in extremely stunted plants. The upper portion resembles a rosette or small flower bouquet. Leaves turn yellow or light green and may roll upward.

Damping-off disease symptoms.

Identification tip:

Stunted or collapsed plants in the field can be a sign of an infection with Pythium spp.

Photo not available

Impatiens necrotic spot symptoms.

Identification tip:

Overall yellowing, dead spots, and general stunting; similar to tomato spotted wilt virus symptoms.

Pepper tobamovirus diseases.

Identification tip:

Although symptoms vary among cultivars and virus or strains they generally include necrosis on any plant part, defoliation, leaf distortion, and/or mosaic symptoms on leaves, stems, and eventually fruit.

Potyvirus mosaic diseases.

Identification tip:

Mosaic patterns are found on at least some leaves, especially younger ones. Plants are often stunted and have curled leaves. Symptoms may be similar to those caused by Cucumovirus mosaic disease.

Powdery mildew.

Identification tip:

A patchy, white, powdery growth  enlarges on the lower leaf surface and at times on the upper surface.

Root and crown rot symptoms.

Identification tip:

Stem lesions start as dark green, water-soaked areas that dry and turn brown. Lesions can girdle the stem resulting in wilting of the plant.

Root knot nematode symptoms.

Identification tip:

Check roots of chlorotic, stunted, or wilted plants for galling to verify a root knot nematode infection.

Tomato spotted wilt virus symptoms.

Identification tip:

Initial symptoms include leaf curling, pale green to yellow discoloration, and necrosis.

Verticillium wilt symptoms.

Identification tip:

Symptoms include yellowing and drooping of leaves on a few branches or on the entire plant. Brown discoloration is visible when the roots and lower stem of a wilted plant are cut open. Symptoms are unlikely to be seen in seedlings.

White mold (Sclerotinia spp.).

Identification tip:

Infected stems eventually become a bleached gray-white and fungal tissue and sclerotia grow on or in the stem. Symptoms can appear at the seedling stage, but are more likely at later stages.