Neem - Vepa - Both polar extracts and neem oil are of primary interest to research scientists as an insecticide. The active insecticidal ingredient, azadirachtin, is also effective against mites and other arthropods. Many of the tree's secondary metabolites have biological activity, but azadirachtin is considered to be of the most ecological importance. Studies have shown a wide spectrum of activity and species affected. It acts by breaking the insect's lifecycle. Research has increased in the past few years as the desire for safer pest control methods increases and it becomes apparent that this tree will be able to play a role in integrated pest management systems. Because of its low toxicity, neem oil is available for general use in most countries, and is permitted for restricted use under the National Organic Program in the United States.