Laboratory evaluation of Melia azedarach (Meliaceae) extracts against the elm leaf beetle (Coleoptera: Chrysomelidae)

In laboratory trials, treatment of elm leaves with an ethanolic extract of Melia azedarach fruits of 2, 5, and 10% concentration significantly deterred feeding by larvae and adults of the elm leaf beetle, Xanthogalleruca luteola (Muller). Larvae forced to feed on treated leaves died without moulting; mortality also increased dramatically in adults fed on treated leaves. Survival and development of larvae sprayed with the extract also were negatively affected, but no effects were observed when adults were sprayed. The effects were generally independent of extract concentration within the range tested, except in the larval-spraying and adult-feeding choice tests, where the lowest dose had little or no significant effect.