Soaps for home landscape control

Greenhouse thrips adults killed by a soap spray on English laurel. The spray was applied with a hand mister. The utility of soap sprays for insect control was demonstrated as early as 1842. During the latter half of the 19th and early 20th centuries, whale-oil soaps, and more commonly fish-oil soaps, were an important part of insect control technology. As the more effective synthetic organic insecticides were developed, research on soap as an insecticide was largely discontinued; but soap continued to be used, principally by home gardeners and in other small-scale situations.