Thrips: Identification, Damage, and Control

Thrips are nearly microscopic insects that rasp soft flower and leaf tissue, then drink plant juices. Leaves develop a shiny silvery or tan cast; black, varnish-like fecal matter appears on undersides. Infested blossoms and leaves may twist or stick together. Thrips attack a wide range of plants.

Plants under stress—especially underwatered ones—are most susceptible. During hot, dry periods, hose down leaves of moisture-loving plants (e.g., rhododendrons). Natural enemies include ladybugs, lacewings, and predatory mites. Soap sprays can also be effective.

Chemical controls: acephate, diazinon, chlorpyrifos, malathion.