Which of the following is a sign of thrips damage?

• A. Silver streaks on leaves
• B. Large holes in leaves
• C. Dark brown stems
• D. Yellowing bloom petals

Answer: (A)

Thrips feed by rasping the surface of plant tissues with their small mouthparts, which injures epidermal cells and causes a translucent, silvery or streaked appearance on leaves. This silvery streaking (often called stippling or bronzing) is a classic sign of thrips feeding, especially on new growth and in flowers where damage is visible as pale, reflective bands.

Other signs listed don’t fit thrips as neatly. Large holes in leaves point to chewing pests like caterpillars or beetles. Dark brown stems suggest stem borers or related issues, not.

Yellowing bloom petals can occur from various stresses or pests, but it doesn’t specifically reflect the silvery leaf streaking caused by thrips. So the presence of silver streaks on leaves best indicates thrips damage.