Populations in the nursery usually disappear when the new spring growth develops. The sixspotted spider mite is most abundant during winter and spring on azalea, especially after a cold winter. Spruce spider mites occur during the hot, summer months, especially on plants under water stress. False spider mites and eriophyid mites occur throughout the year, but predominantly during the summer and fall months. Spider mites feed by penetrating the plant tissue with their mouthparts and are found primarily on the underside of the leaf.
All spider mites spin fine strands of webbing on the host plant - hence their name.
When twospotted spider mites remove the sap, the mesophyll tissue collapses and a small chlorotic spot forms at each feeding site. It is estimated that 18 to 22 cells are destroyed per minute. Continued feeding causes a stippled-bleached effect and later, the leaves turn yellow, gray or bronze. Complete defoliation may occur if the mites are not controlled. Southern red mites first attack the lower leaf surface.