Which type of oil is safe for plant applications and acts as an insecticide by smothering insects?

Horticultural oils are specifically designed for safe application on plants and function as an effective insecticide by smothering insects. These oils create a thin film over the surface of the pests, preventing them from breathing and eventually leading to their demise. They are generally derived from petroleum products or are vegetable oils and can be used to control a variety of soft-bodied insects, such as aphids and spider mites, without causing significant harm to the plants or beneficial insects when used correctly.

In contrast, hydraulic sprayers, while helpful for applying products, do not inherently possess insecticidal properties. Insecticidal soaps are effective against pests as well, but their mechanism of action differs from horticultural oils; they act primarily by disrupting the cell membrane of insects, which is not the same smothering method used by horticultural oils. Lastly, the term insecticides encompasses a wide range of chemical products that may not always be safe for all plants or are designed for specific pest control, potentially leading to adverse effects on beneficial organisms or the environment.