Tarnished Plant Bug Infestation in a Garden

Tarnished plant bug (via Wikimedia Commons, CC BY-SA 2.0)

Tarnished plant bugs are a common garden pest that feed on a variety of plants, including fruits, vegetables, flowers, and ornamental shrubs. These pests are known to cause damage to the leaves, stems, and fruit of plants, resulting in wilted or discolored foliage, and stunted growth.


  • Leaves may turn yellow or brown, or have dark spots or streaks on their surfaces.
  • Stems and shoots may become wilted or discolored, and growth may be stunted.
  • Fruit may be distorted, deformed or have dark specks on their surface. In severe cases, the fruit may become unmarketable.
  • Flowers may be damaged, causing reduced production of fruit and seeds.
  • Tarnished plant bugs also cause damage to seeds, reducing seed viability and germination rate.

It is important to note that these symptoms can be caused by a variety of other factors, including disease, environmental stress, and other types of pests. If you suspect a tarnished plant bug infestation, it is best to consult with a knowledgeable professional or extension agent for a proper diagnosis and recommended course of action.

What is a Tarnished Plant Bug

  • The body of the tarnished plant bug is about 1/4 inch long and has a slightly flattened, oval shape with a distinctive shield shape.
  • The body is metallic brown or bronze in color and is covered in fine hairs.
  • Antennae are long and segmented, and legs are also long and thin.
  • The head is small and rounded, and the eyes are large and prominent.
  • The mouthparts are piercing-sucking, and are used to feed on plant sap.
  • The wings are thin and membranous, and are folded flat over the body when at rest.
  • Tarnished plant bugs have a distinctive “zipper-like” pattern on the wing margins, which is a diagnostic characteristic of the species.

Treating a Tarnished Plant Bug Infestation

It may be necessary to use multiple methods to effectively control a tarnished plant bug infestation. For example, removing the bugs by hand or vacuuming can provide immediate relief, while cultural controls such as crop rotation and proper garden hygiene can help to prevent future infestations.

Physical Removal

  • Hand picking: This method is effective for small populations of tarnished plant bugs. Simply grab the bugs by hand and drop them into a bucket of soapy water to kill them. This method can be time-consuming, but it is safe and eco-friendly.
  • Row covers: Using row covers to physically exclude the bugs from the plants can be an effective method of control. The covers should be placed over the plants when they are small and removed when the plants start to bloom.
  • Vacuuming: A handheld vacuum can be used to remove the bugs from the plants. Simply hold the vacuum nozzle close to the plant and suck up the bugs. The bugs can be disposed of in a bucket of soapy water.

Cultural Control

  • Proper garden hygiene: Removing and disposing of plant debris and weeds can reduce the number of alternate hosts for the bugs and make the garden less attractive to them.
  • Crop rotation: Planting crops in a different location each year can break the life cycle of the bugs and reduce their populations.
  • Companion planting: Planting companion plants that repel the bugs or attract natural predators can help to control their populations. Examples of companion plants that repel tarnished plant bugs include garlic, marigolds, and chives.

Chemical Control

  • Pesticides: Applying an appropriate insecticide according to the label instructions can be effective in controlling tarnished plant bugs. Choose a product that is labeled for the specific type of plant you are treating, and follow the label instructions carefully. Some common insecticides used to control tarnished plant bugs include carbaryl, permethrin, and spinosad.
  • Soaps and oils: Insecticidal soaps and horticultural oils can be used to smother the bugs. The products are mixed with water according to the label instructions and applied to the plants. The soaps and oils work by clogging the spiracles (breathing pores) of the bugs, causing them to suffocate.