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Department of Entomology

Department of Entomology
123 W. Waters Hall
1603 Old Claflin Place
Kansas State University
Manhattan KS 66506-4004

785-532-6232 fax

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Soybean Pests

Spider Mites (Tetranychidae)


Adult two-spotted spider mites with egg.


Typical spider mite damage to soybean.


Damaged leaflet.

Heavy infestations of spider mites, particularly in dry years, can cause leaves to turn yellow, then gray-green, and finally bronze. Leaves prematurely drop from plants. Treatment decisions are not easy because drought stress often makes assessment of mite damage difficult. Plants losing more than 50 percent of their foliage during bloom and pod set may stop producing foliage until more favorable growing conditions return and lost leaf area is replaced. Treatments may be beneficial if significant pod or seed filling remains and leaves have not yellowed. The use of drop nozzles may enhance control by improving coverage of the undersides of leaves. Complete control is difficult to achieve. Mite problems typically developed near gravel roads (where road dust stressed plants by coating leaf surfaces), or downwind of newly swathed alfalfa fields, or mowed roadside rights-of-way.

Please refer to the most recent version of the Soybean Insect Management Guide for control options.

Page last updated 11/01/2013 by J.P. Michaud.