Four Lined Plant Bug Infestation in a Garden

Four lined plant bug (WanderingMogwai via Wikimedia Commons, CC BY-SA 4.0)

Four lined plant bugs (Poecilocapsus lineatus) are common garden pests that feed on a variety of plants, including vegetables, fruits, and ornamental plants. An infestation of four lined plant bugs can cause damage to leaves, stems, and fruit of the affected plants.


  • Yellow or white stippling on the leaves caused by the bug piercing the plant’s leaves and sucking out the sap, leaving small white or yellow spots on the surface.
  • Brown or black speckling on the fruit due to the bug feeding on the fruit, leaving small, dark marks on the surface.
  • Wilted or distorted leaves or stems caused by the bug’s feeding, which can disrupt the plant’s normal growth patterns, causing it to wilt or grow in an abnormal shape.
  • Reduced growth or stunted plant development resulting from repeated or prolonged feeding by the bugs, which can reduce the plant’s overall health and hinder its growth.

What is a Four Lined Plant Bug

  • Approximately 1/4 inch in length, with a slightly flattened body shape.
  • Bright green or yellow-green color with four black lines running lengthwise on its back, which are parallel to each other and provide the bug with its common name.
  • Two black spots on each side of its thorax, which are prominent and easily noticeable.
  • Wings fold flat over its back when at rest, giving the bug a compact appearance.
  • Elongated head and legs that are well adapted for piercing and sucking.
  • Long, slender antennae that are slightly shorter than its body length.

Treating a Four Lined Plant Bug Infestation

Multiple methods may be necessary to effectively treat a four lined plant bug infestation in a garden. It is important to monitor the plants regularly and assess the effectiveness of each control method, adjusting as necessary to achieve the best results.

Physical Control

  • Hand picking: Remove the bugs by hand and dispose of them in a container filled with soapy water. This is a time-consuming method, but it is effective for small infestations.
  • Row covers: Cover the affected plants with row covers to prevent the bugs from accessing the plants. This is an effective method for preventing the bugs from reaching the plants, but the covers must be removed to allow pollination and harvesting.
  • Pruning: Prune off the affected leaves and stems to reduce the number of bugs on the plant. This method can be used in conjunction with other control methods for a more comprehensive approach.

Chemical Control

  • Insecticidal soap: Apply insecticidal soap to the affected plants, following the manufacturer’s instructions. Insecticidal soap works by breaking down the bug’s outer layer, causing it to dehydrate and die.
  • Neem oil: Apply neem oil to the affected plants, following the manufacturer’s instructions. Neem oil works by interfering with the bug’s feeding and reproductive abilities.
  • Pyrethrin: Apply pyrethrin to the affected plants, following the manufacturer’s instructions. Pyrethrin is a natural insecticide that works by quickly paralyzing the bug’s nervous system.

Cultural Control

  • Crop rotation: Avoid planting the same type of plant in the same location year after year, which can encourage a build-up of four lined plant bugs in the soil. Instead, rotate the type of plant that is grown in each location to prevent the bug population from becoming established in one area.
  • Sanitation: Remove and dispose of any plant debris and weeds near the affected plants to reduce the bug’s habitat. This will make it more difficult for the bugs to survive and reproduce.
  • Companion planting: Planting herbs or plants that repel four lined plant bugs near the affected plants can deter the bugs from feeding. Examples of plants that repel four lined plant bugs include mint, basil, and chives.

Biological Control

  • Beneficial insects: Introduce predators of the four lined plant bug, such as ladybugs, lacewings, and predatory stink bugs, to the garden to control the bug population. These predators will feed on the four lined plant bugs, reducing their numbers over time.
  • Natural enemies: Encourage the presence of natural enemies of the four lined plant bug, such as parasitic wasps, by planting a diversity of plants in the garden. These natural enemies will help to control the bug population without the need for chemical control methods.