The insecticidal and acaricidal actions of compounds from Azadirachta indica (A. Juss.) and their use in tropical pest management.
The pest control potential demonstrated by various extracts and compounds isolated from the kernels and leaves of the neem plant (Azadirachta indica) is reviewed, and appears to be of tremendous importance for agriculture in developing countries. Laboratory and field trial data revealed that neem extracts are toxic to over 400 species of insect pests some of which have developed resistance to conventional pesticides, e.g. sweet potato whitefly (Bemisia tabaci), the diamond back moth (Plutella xylostella) and cattle ticks (Amblyomma cajennense and Boophilus microplus). The compounds isolated from the neem plant manifest their effects on the test organisms in many ways, e.g. as antifeedants, growth regulators, repellents, toxicants and chemosterilants. This review strives to assess critically the pest control potential of neem extracts and compounds for their use in the tropics. This assessment is based on the information available on the wide range of pests against which neem extracts and compounds have proven to be toxic, toxicity to non-target organisms, e.g. parasitoids, pollinators, mammals and fish, formulations, stability and phytotoxicity.