The leaves are the structure (matter excels)
more abundant in the neem plant for the production
of extracts. Besides it, the most common limonoids
with higher activity over insects found
in the neem plant are polar compounds (azadirachtin,
salanin and 3- tigloylazadirachtol). That
is the reason why the leaf extract in methanol
was chosen for the bioassay. The determination
of the azadirachtin levels from the leaf extract in
methanol was performed according to Forim et al.
(2010).