Spider Mites

Posted by & filed under Don Buma Blog, Garden News.

spider mite stippling on bean leaves spider miteThe hot, relatively dry weather that we are currently experiencing often encourages population buildups of spider mites. Damage caused by spider mites is called stippling, see photo below, and occurs on the upper surfaces of leaves.  Associated with this stippling will be very fine webbing on the underside of the leaf.  Vegetable plants affected by spider mites include beans, peppers, tomatoes and potatoes. Spider mites are not true insects, but are more closely related to spiders. They are tiny and generally very difficult to see. Their characteristic damage and webbing are the most obvious signs of their presence. If you think mites may be present, hold a sheet of white paper beneath a leaf and tap the leaf. If present, the mites will be dislodged and can be seen as tiny specks moving about on the paper. Spider mite control can be difficult. A strong spray of water, on the underside of the leaves where they feed, can be used to remove the mites but is generally more challenging than it sounds as a fairly high-pressure directed spray is needed to dislodge the mites. Chemical controls include horticultural oils and insecticidal soaps that are best applied, to the undersides of the leaves, early in the morning before the plants become stressed by the heat of the day.