By Alicia Alexander, IPM intern
The harlequin bug is a pest to many agricultural plants for much of the southern US. It’s shield shaped and black with brightly colored markings that are usually red, orange, or yellow. An adult harlequin bug is anywhere from 7mm to 10mm in length. The harlequin bug’s eggs are white and barrel shaped with black bands. These eggs are about 1mm long and are laid in clusters on foliage. Newly hatched harlequin bugs cannot fly and have a more circular shape.
Signs of the harlequin bug would be stippling (white blotches) on your plants where the bug has been feeding. This is from the harlequin bug sucking fluid from the plant tissue. This can cause the host plant to wilt, turn brown and eventually die. A successful way to try and control these bugs would be to manually crush eggs, nymphs, and adults. Look for egg clutches underneath leaves to remove. Removing crop debris will help eliminate overwintering sites. Synthetic pyrethroid insecticides are also an option if labeled for the crop, but control is sometimes difficult to achieve.
The harlequin bug is a stink bug and will produce an odor when disturbed. These bugs are not toxic to humans.