Sticky cards are an important tool for early detection of pests and an important component of an effective scouting program. Sticky cards will only trap winged insect pests like thrips, whiteflies, fungus gnats, leafminers, leafhoppers, shore flies, and winged aphids.
Random plant inspections are still needed to scout for nonwinged pests or stages, such as immature whitefly nymphs, thrips larvae, spider mites, broad mites, scale insects, wingless aphids, and mealybugs crawlers.
Inspect the cards regularly in combination with plant inspections to detect pest outbreaks early and allow for prompt action (Figure 2). Most greenhouse growers use 3” x 5” sticky cards. Yellow sticky cards work best for general pest monitoring. Change the cards weekly.
Place cards just above the plant canopy (Figure 3). Use three to four cards per 1,000 sq. ft. or a minimum of one card per 1,000 sq. ft., with additional cards placed near entrances, vents, sidewalls, and areas where pests are likely to enter the greenhouse (Figure 4). You can also place extra cards over especially problem-prone species or cultivars.
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