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Posted 20 December 2012. PMN Crop News.

Plants in Your Greenhouse? Scout for Thrips and Aphids Now

Source: Michigan State University Press Release.

East Lansing, Michigan (December 3, 2012)--Some growers have already noticed an early infestation of thrips or aphids. Check all incoming cuttings, plants under the benches, overwintering perennials and any new plugs. If this is the case in your greenhouse, step-up the scouting, spray the hot spots, and get them under control now.


Michigan State University Extension advises that growers place yellow sticky cards in their plugs and cuttings to detect thrips activity. They can also tell you about shorefly and fungus gnat levels.

If you detect increasing numbers of thrips or aphids at this time, consider the following treatment choices:

Thrips: Aria, Avid, Mesurol, Orthene 97, Overture, Pedestal, Pylon, Safari (spray or soil drench), Sanmite, Tristar, and Conserve. Note: some thrips may be resistant to Conserve and Safari.

Aphids: Aria, Azatin, Benefit, BotaniGard, Decathlon, Discus, Distance, Endeavor, Enstar II, Flagship, Kontos, Marathon, Ornazin, Orthene 97, Precision, Safari, Tame, Talstar, Tristar.

The idea is to keep greenhouses as clean as possible during winter to avoid an explosion of activity in March and April when conditions are right for the insects. Some good scouting and spot-spraying at this time will save many headaches later on.