In laboratory choice and no-choice bioassays, treatment of elm leaves with extracts obtained from unripe fruits and green or senescent leaves of Melia azedarach at 1-10% concentration significantly deterred feeding by adults of the elm leaf beetle, Xanthogaleruca luteola. Also, in no-choice tests, adults fed on leaves treated with 2, 5 or 10% extract showed a dramatic increase in mortality rates. Extracts from the different plant structures were similarly active, and starvation as a consequence of their strong antifeedant activity could play a significant role in the high mortality values observed.