Several months ago, I repotted my African Violets and now they are full of flying knats. I bought Miracle Grow African Violet Potting Soil and have never had insects before. I lost one plant due to these pests as the roots were eaten. I also bought Miracle Grow Nature Insecticide Soap and sprayed the soil. Nothing is getting rid of these pests and they are flying in the house. I have an emotional attachment to my violets and have nurtured them for 10 years, repotting and transplanting them. Now I only have one plant left and don't want to lose it! What can I do?