The Colorado State University Extension recommends the use of insecticidal soaps, neem and pyrethrins for the effective control of bugs and insects on indoor plants.
Insecticidal soaps are derived from the potassium salts in fatty acids. The chemical damages cells membranes of targeted pests and causes death through desiccation. Neem is the natural oil found in the Indian neem tree. The insecticide repels pests and hinders their feeding process, suppressing growth and causing death. Pyrethrins are also natural chemicals found in certain daisy species. The pesticide works rapidly but persists for only a few hours.
Products containing insecticidal soaps are most effective when used on soft-bodied pests such as aphids and mites. The insecticides are effective only in their liquid form and lose efficacy upon drying. Neem-based pesticides control thrips, aphids and whiteflies. Pyrethrins are most effective on whiteflies, scales, thrips and aphids.