Inspect incoming vegetative cuttings for insects

Recent observations in Michigan greenhouses indicate that some growers may be bringing in unwanted hitchhiking insects on the starter material they are receiving, reports Mich. St. Univ. Extension senior district extension horticulture and marketing educator Tom Dudek. He has seen thrips and mealybugs on cuttings that were received by a grower who placed them into an empty greenhouse.
Dudek advises growers to carefully inspect cuttings with a hand lens if necessary or to tap the cuttings over a white sheet of paper to see if dislodged thrips or spider mites may be moving around. If pests are present, the plant material should be isolated and the appropriate controls applied to reduce their spread. Dudek said a sticky card monitoring program should be started and the cards should be monitored once or twice a week to determine pest population levels.

Pictured: Growers receiving cuttings from suppliers should inspect them thoroughly for hitchhiking pests such as spider mites before moving the plants into a greenhouse.
Photo by Dan Gilrein, Cornell University