Thrips are small, slender insects with feathery wings. They damage plants by sucking their juices, stinging them, and rasping at fruit and leaves to cause scars. Leaves may turn pale and silvery, and then die. The pests are attracted especially to white blossoms. Damaged rosebuds turn brown and may open to show distorted petals. Thrips may transmit the virus that causes spotted wilt on tomato.

Infested flowers and buds should be promptly removed to avoid infesting plantings. Plants under water stress are particularly susceptible to trouble; see to it that plants are properly watered or irrigated in hot seasons, especially in dry areas. On a large scale, you can get around thrips by not growing susceptible crops in consecutive years; a three-year crop rotation will help.

Because many thrips have a wide range of hosts that includes many weeds, they can often survive in the garden area even if no susceptible crops are grown. So, control of weeds and volunteer plants may be well worth your while for this pest alone, especially if tomato spotted wilt virus has been a problem. The area of clean culture should extend for some distance; thrips are weak fliers, but they can beat the air hard enough so that the wind will blow them a good ways. In still air the smaller species can manage a speed of 10 centimeters a second, while larger thrips can hit 50 centimeters a second. But the wind usually blows them wherever it will. Thrips stick to the ground when stiffened by the cold, and won’t take off if the temperature is below 64° to 69°F.