Check incoming plugs and cuttings for hitchhiking pests

Tom Dudek, Mich. St. Univ. Ext. senior district ext. horticulture and marketing educator, reports that Michigan growers are receiving starter material that has unwanted pests. Some examples include: scaevola with mealybugs and whitefly; ivy geraniums with broad mites, spider mites and mealybugs; cordyline with thrips and spider mites; lantana with whitefly; New Guinea impatiens with impatiens necrotic spot virus indicating the presence of thrips; asparagus fern and some herbs with aphids.
Dudek reminds growers to carefully inspect plugs and cuttings to avoid bringing these pests into their greenhouses early and then having to try to control them throughout the production season. He said an initial inspection upon arrival and the use of sticky cards will help growers to avoid problems later. If sticky cards or scouting indicate an increase in aphids, mites, thrips, fungus gnats or whiteflies, application of control measures may be necessary to reduce populations to acceptable levels.