Harlequin Bug on Vegetables

Life cycle/habits

• Adults overwinter in sheltered locations in or near gardens, including winter crops and organic debris.
• In spring, adults emerge and deposit eggs on leaf undersides.
• Nymphs and adults feed by piercing leaves to suck nutrients.
• Harlequins are a stink bug and adults will produce a smelly odor when disturbed.
• They love the annual flower, cleome.
• Two or three generations occur per year.

Host plants

• Cole crops (a.k.a. crucifers or brassicas) such as cabbage, broccoli, cauliflower, turnip, collards, horseradish, arugula.
• Many other crops may be affected, including asparagus, bean, cantaloupe, onion, pea, potato, squash, and tomato, as well as fruits such as grape, peach, pear, and raspberry.

Signs/symptoms

• White spots, known as stipples, result from the piercing-sucking feeding of nymphs and adults.
• Leaves brown and look tattered.
• Plants may wilt, be deformed, or, under severe infestation, die.

Monitoring

• Turn leaves over to spy egg clutches.
• Watch leaves for white or yellow blotches, distortion, and browning.
• The bright colors of nymphs and adults makes them easy to spot, though they will hide under leaves when threatened.

Prevention/control

• Clean up the garden at season's end. Remove all crop debris to eliminate overwintering sites.
• Search out and manually crush eggs, nymphs, and adults.
• Use floating row cover to exclude this pest.
• Spray nymphs with insecticidal soap alone or in combination with pyrethrum or use neem oil.
• Cleome can be grown as a trap crop. Spray infested cleome with an insecticide or pull plants up and dispose of in black trash bags.
• Check catalogs for resistant varieties of many cruciferous plants.