Some thrip species are beneficial insects, but others do serious damage to flowers, fruits and vegetables. Different types may attack specific plant families, but these pests strike garden favorites from roses and raspberries to tomatoes and onions. Adult thrips feed on plants and lay eggs on or inside plant leaves. The eggs hatch into hungry larvae that can mature in as little as two weeks. Multiple generations occur in a single growing season. Thrips also can transmit serious plant diseases.
Common thrips are tiny, rice-shaped insects best viewed with a magnifying glass. Their slender bodies are often just 1/32 to 1/20 inch long. Adults vary in color from pale, translucent amber to brown or black. They have two pairs of wings fringed with distinctive, featherlike hairs. Wingless nymphs are smaller and lighter in color.
Signs or Damage of Thrips
Thrips damage plants by rasping and slicing plant tissue and feeding on oozing sap. They typically feed on the undersides of leaves, following along leaf veins. Damage appears on the upper sides of leaves as silvery white specks or small lines. Plants become stunted. Leaves crinkle and drop. Fruit becomes deformed, scarred or scabby.
How to Control Thrips
Because of their small size, thrips often go unnoticed until damage is done. Effective treatment starts early in the season, before populations grow. GardenTech brand offers highly effective options to kill thrips and protect plants:
- Sevin Insect Killer Ready to Use2 simplifies treating individual plants and small garden areas. Adjust the spray container's nozzle to spray widely or narrowly and kill thrips on contact. Cover all plant surfaces thoroughly, including buds, fruit and the undersides of leaves.
- Sevin Insect Killer Concentrate and Ready to Spray provide economical and efficient options to treat larger vegetable gardens and ornamental plantings. These products kill by contact and keep protecting against thrips for up to three months. Cover all plant surfaces thoroughly. Give special attention to the undersides of leaves.
- Sevin Insect Killer Dust Ready to Use starts killing thrips immediately upon contact. Use the convenient shaker container to apply a thin, uniform layer of dust to plant leaves, stems and flowers. Treat at the first sign of thrips or their damage.
Thrip Control Tip: Thrip damage and reproduction peak during hot, dry conditions. Keep gardens irrigated well to reduce susceptibility to thrip damage.
Always read product labels thoroughly and follow instructions, including guidelines for listed plants and pests, application frequency and pre-harvest intervals (PHI) for edible crops.
GardenTech is a registered trademark of Gulfstream Home and Garden, Inc.
Sevin is a registered trademark of Tessenderlo Kerley, Inc.
- "Thysanoptera" by Mick Talbot licensed under CC BY 2.0
- "Tubuliferan thrips (several stages in life cycle), and feeding injury to leaf" by Scot Nelson licensed under CC BY 2.0 (public domain)
- "Pole beans: Thrips feeding injury" by Scot Nelson licensed under CC BY 2.0 (public domain)
- "Onion thrips (Thrips tabaci) Lindeman, 1889" by Alton N. Sparks, Jr. at University of Georgia (Bugwood.org) licensed under CC BY 3.0 US