There are many generations per year. Four or more mites per leaf or one severely damaged leaf per plant prior to pod-fill causes concern, as crop yields are affected. If mites have exceeded the damage threshold, apply an insecticide. If the infestation is caught early enough, it is necessary only to treat hot spots on the edges of the field where the mites are moving in from their overwintering sites. This will help to prevent the spread of mites to other parts of the field and may reduce the need for further treatment.
Heavy rainfall reduces mite populations in soybeans.
Mites can be a problem in dry years in soybeans planted in no-till winter wheat stubble which had been underseeded to red clover. Mites can build up in red clover in the previous year, and when the clover is burned off with herbicide in the spring the mites will move to young soybean plants. Slugs Conservation tillage practices provide a favourable environment for slugs to develop. These moisture-loving creatures are extremely sensitive to solar dehydration and crop residues on the surface provide both cover and high humidity. Poor drainage will increase the potential for slug damage by increasing humidity.