Patterns of bioactivity and herbivory on Nothofagus species from Chile andNew Zealand

Nothofagus species from Chile and New Zealand were surveyed in the field fo r invertebrate abundance and leaf feeding damage and in the laboratory for antifeedant activity against leafrollers (Ctenopsteustis obliquana, Epiphya s postvittana), deterrent activity against pea aphid (Acyrthosiphon pisum), insect growth regulatory activity (Oncopeltus fasciatus), nematicidal acti vity (Caenorhabditis elegans), antibiotic activity (Pseudomonas solanaciari um), and general toxicity. A data matrix indicated that N. alessandri and N , pumilio most likely have a chemical barrier to insect attack as leaves sh owed low faunal abundance, low herbivory, and activity in the leafroller an tifeedant, aphid deterrent, and nematicidal assays. A chemical examination of N. alessandri that used the leafroller antifeedant test to guide the sep aration yielded an active fraction containing the flavonoid, galangin, and the stilbene, pinosylvin, which appear to act in concert to deter leafrolle r feeding. The discovery of the phytoalexin, pinosylvin, in the leaves, rai ses the possibility that Nathofagus in general, and N. alessandri in partic ular, may have induced chemical defense mechanisms.