Root mites can be detected only taking out the plant from the ground. Rift bulbs gippeastruma diseased root mites. These mites are impaired primarily bulbous plants. They gnaw tissue bulbs. In this case, the initial stage of lesion seen a damn place and moves mites, but mites gradually gnaw whole onion. A damaged bulb can easily fall apart in your hands or break in it will drive out all the interior fabrics, there is only white trash, and mites are not visible the naked eye.
Control measures. Before landing, carefully inspect the bulb. Promotes the appearance of root mite excessive moisture of the soil. You do not need watering less than it needs, it is necessary to prevent stagnation of water in the roots, ie, do good drainage and drain the water from the sump. Affected bulbs and plant roots watered or maintained an insecticide solution (fitoverm, Fufaev, aktellik).