four-lined plant bug nymphs

Four lined plant bug nymph on forsythia. Photo: Dawn Dailey O'Brien, Cornell University, Bugwood.org

Updated: June 22, 2021

What are plant bugs?

  • Plant bugs are small sucking insects (2-9mm) that feed on the leaves of many herbaceous plants.
  • The plant bugs feed by piercing the leaves with their tube-shaped mouthparts, injecting an enzyme into the leaf tissue, and sucking up the partially digested fluid.
  • Damage to leaves may appear as stipples (tiny white spots), small round holes and distorted leaves.

Types of plant bugs

Four lined plant bug

  • A pest in the garden in May and June (one generation per year).
  • The adults are 3/16 of an inch long and yellowish-green with 4 black stripes down the back.
  • The nymphs (immature bugs) are red with yellow and black wing pads partially covering the body.
  • This bug feeds on over 250 herbaceous plants.
  • Damage from this plant bug begins as yellow stipples or spots, eventually becoming brown to black necrotic spots. In large infestations, these spots coalesce and cause leaves to turn brown.
  • Four-lined plant bugs are quick and difficult to detect, and only a few can cause noticeable damage.
  • Because they move so quickly, they are difficult to control with a contact insecticide such as insecticidal soap or horticultural oil.
  • Many plants will outgrow the damage by mid-summer.
four-lined plant bug adult

Four lined plant bug (adult). Johnny N. Dell, Bugwood.org

four-lined plant bug damage on leaves

Four-lined plant bug damage. Photo: Matthew Borden, University of Florida, Bugwood.org

Yucca plant bug 

  • Is a pest of yucca wherever it is grown.
  • The leaves are stippled, have black fecal spots, and eventually turn yellow.
  • The adult bug is 1/8th inch long, stout, and blue-black with a reddish head and thorax.
  • The nymphs (young plant bugs) are red and may be found in large numbers feeding on the leaves.
black and red yucca plant bugs

Yucca plant bugs. Photo: Jim Baker, North Carolina State University, Bugwood.org

Honeylocust plant bug

  • Is pale green with wings held flat on the back.
  • Immature bugs look just like the adults, only smaller and with short wing bugs.
  • The immature plant bugs feed on emerging leaflets in spring causing them to become distorted with yellow blotches.
  • Eventually, the distorted leaves (see above below) turn brown and fall off.
  • Adults appear around May and are gone by the end of June.
honeylocust plant bug damage

Honeylocust plant bug damage. Photo: Whitney Cranshaw, Colorado State University, Bugwood.org

honeylocust plant bugs

Honeylocust plant bugs. Photo: John A. Davidson, University of Maryland

milkweed bugs

Milkweed bugs

black and tan tarnished plant bug

Tarnished plant bug on sunflower. Photo: Russ Ottens, University of Georgia, Bugwood.org