Authors: Gary L. Hein & Frank B. Peairs[1]
Identification (and life cycle/seasonal history)
The two-spotted spider mite, Tetranychus urticae Koch, is a minute arthropod found in colonies under webbing on the lower surface of leaves. Infestations are often associated with drought stress and hot, dry weather conditions.
Plant Response and Damage
Damaged leaves will have a silvery or bronzed look. Little is known about the effect of spider mite feeding on dry bean yield and quality, but the earlier in crop development that infestation starts, the more likely it is that significant losses can occur.
Management Approaches
Infestations are rare in the region with the possible exception of western Colorado. Damage is most often seen in dry years adjacent to areas of broadleaf weeds that have been cut down or severely stressed. Chemical control of spider mites is difficult and seldom recommended.
Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.
