Eco-friendly Control of Thrips

Poorly developed flowers, stunted plants and silvery streaks on leaves are indications thrips may be feeding on your plants.

These tiny insects have file-like mouthparts they use to puncture the outer surface of leaves, stems and flowers and suck out plant sap. They are very small and difficult to detect. Hold a white piece of paper under the plant and shake. Or remove the petals of damaged flowers, place in a sealed jar with 70% alcohol and shake the jar to dislodge and detect the pests.

Control is difficult and often not needed as the damage is discovered after the thrips have finished feeding.

Provide the proper growing conditions and care for your plants. Avoid excess nitrogen that promotes lush succulent growth these pests prefer. And remove spent flowers that tend to harbor the insects. Manage weeds in the garden and keep thrip-susceptible plants away from weedy areas where the pest populations tend to be high.

A bit more information: Beneficial insects like predatory thrips, green lacewings, minute pirate bugs and some parasitic wasps feed upon plant damaging thrips. Invite these good bugs into the garden by planting a diversity of plants and avoiding persistent pesticides. Visit the University of California IPM online for more details on this pest.