They quickly scurry into hiding when the plant is touched or they sense changes in the environment, so they are readily detected by exhaling on a blossom held over your hand, or tapping the blossom onto a white sheet of paper. The carbon dioxide in the breath will cause the thrips to exit the bloom and fall into your hand. Another sign of their presence is pollen spread downward from the anthers, spoiling the blooms. This is more noticeable on the darker-colored flower forms. The piercing and rasping caused by feeding thrips damages plants.
Thrips also are important vectors for tomato ringspot virus.
Effective insecticides include azadirachtin, fenoxycarb and spinosad. Consult the label for dosage rates and safety precautions. Control in the home begins with buying clean plants and if needed, handpicking of infested blossoms. Control of thrips is especially important because they can vector tomato spotted wilt virus. State of Connecticut Disclaimer and Privacy Policy.