Thrips are a common pest of many garden and greenhouse plants. Some species cause leaf or flower distortion; others cause a flecking of the leaves, producing a bleached appearance. Thrips feed by rasping the soft plant tissue, then sucking the released plant sap. Some leaf thrips leave unsightly, black, varnishlike spots of excrement around the areas where they feed. The black or brown adults have wings. They can spread rapidly by flying to new plants; or they may be blown long distances by the wind. They lay their eggs either on the plant or in surrounding weeds. The young are yellow or white and spindle shaped.
Spray the leaves or buds and flowers with an insecticide containing acephate or malathion. Make sure your plant is listed on the product label. Remove and destroy infested buds and flowers.
