Production Of Chemical Insecticides Using Neem Oil And The Processes Involved

Neem (Azadirachta indica A. Juss) is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has huge insecticidal property and is thus commercially exploitaed. During the last two decades, apart from the chemistry of the neem compounds, considerable progress has been achieved regarding the biological activity and insecticidal applications of neem. It is now considered as a valuable source of unique natural products for botanical insecticides against various pests. This review gives a bird’s eye view mainly on the biological activities of some of the neem compounds isolated, insecticidal actions of the neem extracts, applications of neem has an eco friendly botanical insecticide in pest management along with their safety evaluation.

Research into the insecticidal effects of azadirachtin, a limonoid from the Neem tree (Azadirachta indica) has been ongoing for some 30 years. Its strong antifeedant, insect growth regulatory and reproductive effects are now well understood and documented.  Antiffedancy varies markedly between species with mosquitoes being particularly sensitive to azadirachtin.  The mode of action of azadirachtin lies in (i) effects on deterrent and other chemoreceptors resulting in antifeedancy and (ii) direct effects on most other tissues studied resulting in an  overall loss of fitness of the insect. The complexity of the molecular structure of azadirachtin has precluded its synthesis for pesticide use although novel synthesis of the parent molecule is now almost complete and research into simpler mimetic substances is ongoing. Applied research has concentrated on a variety of natural formulations from neem seed kernels which contain azadirachtin together with several structurally related  molecules. 

This study brings the reader  up to date with both pure and applied research in the field, and provides a detailed overview of present thinking into the mode of action of azadirachtin. Wherever possible comparative approaches have been made between species of the effects of pure azadirachtin and areas for future research are indicated.