Soaps and detergents may also remove the protective waxes that cover the insect, causing death through excess loss of water. Soap-Detergent Sprays Soaps and detergents act strictly as contact insecticides, with no residual effect. To be effective, sprays must be applied directly to and thoroughly cover the insect. Several insecticidal soaps are distributed for control of Insects and mites. Available under a variety of trade names, the active ingredient of all is potassium salt of fatty acids.
Soaps are chemically similar to liquid hand soaps.
However, there are many features of commercial insecticidal soap products that distinguish them from the dishwashing liquids or soaps that are sometimes substituted. Some household soaps and detergents also make effective insecticides. In particular, certain brands of hand soaps and liquid dishwashing detergents can be effective for this purpose. They are also substantially less expensive. However, there is increased risk of plant injury with these products.