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. Several recently developed oils extend this usefulness to flowers, vegetables and other herbaceous plants.
Oils also can control some plant diseases, such as powdery mildew.
Oils used to protect plants have been called by many names, but perhaps horticultural oils best describes them. Oils have different effects on pest Insects. In some cases, oils also may act as poisons, interacting with the fatty acids of the insect and interfering with normal metabolism. Oils also may disrupt how an insect feeds, a feature that is particularly important in the transmission of some plant viruses by aphids. Oils pose few risks to people or to most desirable species, including beneficial natural enemies of insect pests.