🐛 Tarnished Plant Bug

Lygus lineolaris · Hemiptera: Miridae

Tarnished plant bugs cause 'cat-faced' or misshapen strawberries, damaged buds in many crops, and distorted plant tips. They're one of the most economically important vegetable pests with almost no public awareness.

Tarnished Plant BugLygusStrawberryCatfacingMiridaeBloom Period
🐛
Risk Level
Fruit and Vegetable Pest
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PestControlBasics Editorial Team
Reviewed by Derek Giordano · Updated 2026
Tarnished Plant Bug identification guide illustration

Illustrated identification guide — PestControlBasics.com

🔍 Identification

Adults: 6mm; oval; brown to tan with yellow, brown, and black irregular markings; distinctive yellow triangle on back (diagnostic). Nymphs: green; similar to aphids but faster-moving and more robust. Found on: strawberry, peach, bean, alfalfa, celery, and hundreds of other hosts. Damage: 'catfaced' (deeply lobed, misshapen) strawberries; blind tips in vegetables; bud and flower drop; distorted growth.

🧬 Biology & Behavior

Overwintering adults emerge early in spring from weedy field margins. They feed on developing buds before crop flowers open — a single bug feeding on a strawberry bud for less than a minute causes the catfacing that ruins the entire strawberry. The polyphagous (many-host) nature means populations build in weeds and then move to crops during bloom. Weed management in field margins is a primary cultural control.

⚠️ Damage & Health Risk

Catfaced strawberries (cosmetically ruined); bud and flower destruction; blind growing tips in vegetables; economic losses in commercial strawberry, peach, and vegetable production.

🔧 DIY Treatment

Pyrethrins or spinosad spray during bloom on strawberries (apply in evening to minimize bee exposure). Row cover through bloom prevents access. Weed management in field margins reduces source populations. Yellow sticky traps for monitoring emergence timing.

👷 When to Call a Pro

Commercial strawberry: spray program guided by trap monitoring; bloom-period spray with pyrethrins is the commercial standard in high-pressure areas.

❓ FAQ

Why are my strawberries misshapen?
Catfaced (deeply lobed, misshapen) strawberries are almost always caused by tarnished plant bug feeding during the bud stage. The bug feeding prevents proper development of the fruit tissue in the affected area. Cool spring conditions that slow strawberry development while lygus populations build also increase pressure. There's no recovery — prevention through bloom-period spray is required.
How do I monitor tarnished plant bugs?
Yellow sticky traps placed at the perimeter of strawberry beds capture adults and indicate population pressure. Beginning monitoring when daytime temperatures reach 60°F consistently. Adult lygus also respond to beat cloth sampling — hold a white cloth under strawberry foliage and tap sharply, counting bugs that fall.
📚 Sources: Texas A&M Fire Ant Project · EPA Safe Pest Control
Published: Jan 1, 2025 · Updated: Apr 7, 2026

🗺️ US Distribution — Tarnished Plant Bug

image/svg+xml
Common Occasional Not Present
States Present
14
Occasional
11
Primary Region
Southeast US
📊 Source: University extension services, USDA, CDC vector data, and published entomological surveys.