Four-Lined Plant Bug

The four-lined plant bug sucks juices from leaves, leaving behind small brown spots and shotgun-like holes, which can be easily mistaken for a leaf-spot disease. Most plants will tolerate a modest amount of damage from these bugs, which can be identified by the characteristic four black lines on their backs. When plants are under severe plant bug attack, their leaves drop off and they become stunted. Four-lined plant bugs feed on a wide variety of garden plants, including squash, potatoes, basil and mint.

The first damage is caused by the nymphs, which hatch in spring from banana-shaped eggs that overwinter on plant stems. After about 30 days, these nymphs become adults. When approached, adult bugs often drop to the ground and hide, which makes them difficult to spot. The four-lined plant bug is active throughout North America.

Prevention and Control

• Remove or mow weeds, especially pigweed, near the garden where these plant bugs like to hide. Plant a trap crop of mint nearby. Four-lined plant bugs prefer mint to most other crops. Be sure to destroy the bugs on the mint plants before they migrate to other plants in your garden.
• Encourage native predators such as bigeyed bugs, damsel bugs, and pirate bugs.
• Cover prized plants with garden fabric to prevent bugs from feeding.