Two-spotted spider mite: Injury and damage

Spider mite injury to soybean can resemble herbicide injury or a foliar disease; however, characteristic signs are tiny yellow spots, or stipples, on leaves. As the injury becomes more severe, leaves turn yellow, then brown or bronze, and finally die and drop off. Soybean plants injured by mites mature early, have increased shattering, produce smaller seeds, and may produce wrinkled seeds. Early and severe mite injury left untreated can completely eliminate yields. More typical mite injury, occurring during late vegetative and early reproductive growth, will reduce soybean yields 40-60 percent. Spider mites can cause yield reductions as long as green pods are present. Soybean plants can recover from substantial amounts of mite injury after treatment, although less compensation is possible in later developmental stages.

Spider mite webbing: Plants heavily infested with spider mites will look dirty, yellow, and covered in webbing. (Photo by David Cappaert)Spider mite webbing: Plants heavily infested with spider mites will look dirty, yellow, and covered in webbing. (Photo by David Cappaert)