Influence of the plant antifeedant, pinosylvin, on suppression of feeding by snowshoe hares

This study investigated the influence of the plant antifeedants, pinosylvin and pinosylvin methyl ether (PME), on suppression of feeding by snowshoe hares (Lepus americanus). Screening bioassays showed clearly that pinosylvin suppressed feeding by hares when sprayed directly on coniferous tree seedlings. Pinosylvin odor, when associated with food (but not mixed with it), also significantly reduced consumption of rabbit chow by hares. Large pen bioassays indicated that both pinosylvin and PME significantly reduced feeding on tree seedlings by hares when the antifeedants were sprayed directly on trees. In field bioassays near Prince George, British Columbia, Canada, pinosylvin sprayed on trees and encapsulated in controlled-release devices of PVC plastic, with an internal wire as a twist-tie for attachment to tree, significantly reduced feeding by hares. Thus, pinosylvin will generate an “avoidance response” in terms of feeding by snowshoe hares. This response is likely triggered by an olfactory pathway based on positive results with controlledrelease devices attached to seedlings. Our study reports the first practical utilization of plant antifeedants for forest crop protection and wildlife management.