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α-Farnesene levels in the outer coating of developing fruit of ten varieties of apple were monitored at fortnightly intervals from fruit set to harvest. The compound was present in all varieties and the total amount on individual fruit increased with increasing fruit size. However, varieties differed in the levels of α-farnesene/unit area of apple skin, with two peaks evident in some varieties during the season. The relationship between varietal and seasonal variation in α-farnesene production and the ecology and behavior of codling moth adults and larvae is discussed.

Crude extracts of root of the resistant pasture plants lucerne (Medicago sativa) and Lotus pedunculatus contain strong feeding deterrents for third instar Costelytra zealandica and Heteronychus arutor larvae. Purified saponins isolated from active crude lucerne root extract markedly reduce grass grub feeding and have an ED of 0.019%. Black beetle larvae are even more sensitive to the material. Separate and chemically distinct feeding deterrent fractions, active against the two insects, have been isolated from Lotus pedunculatus root. The role of feeding deterrents in mediating the non-preference of these insect pests for lucerne and Lotus is discussed.

Crude extracts of the root of the resistant legume,Lupinus angustifolius, showed feeding deterrent activity toCostelytra zealandica andHeteronychus arator larvae. Nine 5-hydroxyisoflavones were isolated from an active fraction and their feeding deterrent activity and antifungal activity was measured. High feeding-deterrent activity was associated with high antifungal activity with some exceptions.