Thrips also are vectors for certain plant diseases. Thrips attack the foliage, buds and flowers of many vegetable, ornamental and flowering plants. B. Use the botanical insecticides azadirachtin or pyrethrins. The latter three predators commonly are found in the garden during the summer and can be captured relatively easily and brought indoors for thrips control in small greenhouses and sun porches. B. Use a forceful spray of water to reduce numbers of thrips on sturdy plants.
High humidity is detrimental to many thrips species.
Periodically flood earthen greenhouse floors to drown pupating thrips. B. Soils high in organic matter seem to favor those thrips that pupate in the soil. C. Quarantine new plants and treat before placing them among established plants. Scale Scale insects are among the most destructive plant-feeding insects. Heavily infested plants often are covered with small, disklike or waxy coverings, and underneath each covering is the scale organism feeding on the juices of the plant.