Western flower thrips cause direct damage by feeding on plant leaves and flowers. Western flower thrips possess piercing-sucking mouthparts, and tend to feed on the mesophyll and epidermal cells of leaf tissues. Symptoms of feeding include leaf scarring, distorted growth, sunken tissues on leaf undersidesFlowers and leaves have a characteristic “silvery” appearance. Western flower thrips also vector tospovirus (Impatiens Necrotic Spot Virus, Tomato Spotted Wilt Virus)
Black fecal deposits may be present in the feeding scars. Damage to plant leaves may also occur when females, using their sharp ovipositor, insert eggs into plant tissue.
See fact sheet Western Flower Thrips Management and Tospoviruses