It has a garlic-like odor and is relatively nontoxic. Neem stops insect feeding and interferes with shedding of their skin. Pyrethrums give a fast knock down of pest insects and are broad spectrum. There are no residues left on crops after spraying with this pesticide. It is a relatively nontoxic, broad spectrum product sometimes found in products containing rotenone.
Rotenone stops insect feeding and is broad spectrum in action.
It leaves no residue on crops and lasts only 3 days once applied to vegetables. Rotenone is very toxic to fish. Ryania is made from ground roots of the ryania shrub of Trinidad. Ryania stops insect feeding and leaves no residue on crops. It is chemically related to nicotine.