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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.

A series of pests have been detected in plantations and urban trees, affecting directly the economy and recreational areas. The elm leaf beetle, Xanthogaleruca luteola Müller (Coleoptera: Chrysomelidae), is an insect pest that skeletonises the leaves of Ulmus spp., trees with a great ornamental value, which can become completely defoliated. The boldo tree (Peumus boldus Molina) is an evergreen plant endemic in Chile that contains secondary metabolites. Proximal analysis and insecticidal effects of extracts obtained from young and mature leaves with water and ethanol from P. boldus were evaluated at various concentrations on X. luteola under laboratory conditions in a completely randomized experiment considering two leaf maturity stages and solvents. Dry weight, water content, ash, and crude fiber leaf flour were significantly different between maturity stages, but the percentage of lipids and proteins were similar. Also, the 50% lethal concentration (LC50) was determined for each extract. The extracts obtained with both solvents were effective in controlling X. luteola adults in the laboratory, reaching over 50% average mortality at concentrations greater than 3.6% (w/v) in the young leaf extract and 4.0% (w/v) in the mature leaf extract. The lowest LC50 was 1.2% (w/v), obtained from the young leaf extract with ethanol after 48 h. This bioinsecticide from the leaves of P. boldus suggests an interesting opportunity for use in integrated pest management of X. luteola.

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Xanthogaleruca luteola (Coleoptera: Chrysomelidae) is an aggressive defoliating pest on elms (Ulmus sp.) worldwide. We evaluated the antifeedant and insecticidal effects of ethanolic and aqueous extracts from Melia azedarach L. green fruits and leaves of Peumus boldus Molina, on X. luteola third instar larvae, the most harmful stage. Five doses of the extracts were applied to fresh elm leaves to determine antifeedant effect evaluating consumed foliar area at 24 h. Insecticidal activity was assessed through daily mortality for 14 d. For each extract an antifeedant index, relative to respective control, and mean lethal concentrations (LC50) were calculated. We found a direct relationship between concentration and both antifeedant and insecticidal effects for all extracts. A dose of 6.1% w/v of ethanolic extract of M. azedarach green fruits significantly inhibited larvae feeding behavior by 91% with a LC50 1.49% at day 8. On the other hand, 3.4% w/v of ethanolic extract of P. boldus inhibited larvae feeding behavior by 81% and LC50 at day 8 was 0.92% w/v. All extracts showed insecticidal effect on X. luteola larvae, and the highest mortalities observed were 79% and 71% with ethanolic and aqueous extracts of P. boldus, respectively. Antifeedant and insecticidal effects observed with M. azedarach green fruits and P. boldus leaf extracts on X. luteola third instar larvae, support the development of botanical insecticides from both tree species in order to contribute to its integrated management.