Certain oils, diluted with water and applied as sprays, can be effective controls of many plant pests.
Horticultural oils are usually highly refined petroleum oils combined with an emulsifiying agent.
Some plant-derived oils also are used. Advantages of oils include safety, effectiveness and limited effects on beneficial Insects. Do not use oils on certain sensitive plants. Plants under drought stress may have increased risk of injury. Various oils have been used for centuries to control insect and mite pests.