Insecticidal activity of Maytenus species (Celastraceae) nortriterpene quinone methides against codling moth, Cydia pomonella (L.) (Lepidoptera : Tortricidae)

The insecticidal effects of nortriterpene quinone methides (pristimerin, ti ngenonee, and 20-alpha-hydroxytingenone) are reported for the first time. T he natural products were isolated from Maytenus sp. (Celastraceae) and thei r effects tested on larvae of codling moth (Cydia pomonella, Lepidoptera: T ortricidae). The three metabolites produce the same effects on codling moth larvae that azadirachtin does, although at higher concentrations, 20-alpha -Hydroxytingenone was the most active compound, showing lethal, antifeedant , and insect growth regulation activities. Pristimerin showed also a high a ntifeedant activity together with its molt effect suppression. Tingenone sh owed the lowest activity. The differences in the activity of the three prod ucts are related to the structure of the E ring.