Several kinds of thrips injure plants both outdoors and in the. They on the surface of the foliage, sucking the sap, and in very bad attacks may even cause death of the plants. Mottling and streaks (often with a silvery appearance) are typical symptoms. They are very active and able to move about rapidly from plant to plant, often in large numbers within the petals of roses, and other . Destroy all weeds and rubbish which are favourite winter quarters for these pests. Organic or gamma-BHC (lindane) sprays tackle these pests. See ROSE — Insect Pests.