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Abstract:
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A study was undertaken of the physical and chemical characteristics and insecticide properties of melia (Melia
azedarach L.) (Meliaceae) fruit and leaves; melia has been introduced in Chile for ornamental purposes. The
physical and chemical properties were evaluated in two stages of fruit and leaf maturity, i.e., green /mature, and
mature/juvenile, respectively. Laboratory bioassays were carried out on Drosophila melanogaster Meigen (Diptera:
Drosophilidae) as an insect model. The diameter of M. azedarach fruit was in the lower limit in relation to other
studies. The flour obtained from green fruit had an average dry weight inferior to that of mature fruit. The average
dry leaf weights were similar in both juvenile and mature states. The green fruits had 50% initial humidity, similar
to juvenile (60%) and mature (57%) leaves, but greater than the mature fruits (44%). The chemical analysis of the
fruit maturity stages determined a slight increase in crude fiber content as maturity increased. There was a decrease
in the lipid content of leaves close to 60% at maturity. Furthermore, an analysis of polyphenols was made using
HPLC-DAD (High Performance Liquid Chromatography-Diode Array Detector), and 14 compounds were identified
as causes of the insecticidal effect of the M. azedarach fruit, of which three would correspond to flavonoids: one
catechin and two kaempherols. Finally, the aqueous fruit and leaf extracts of M. azedarach were effective insecticides
on D. melanogaster, reaching 90% mortality (125 000 mg kg-1) with juvenile leaves and 73.3% (10 700 mg kg-1) with
green fruit. |