Insect Defoliators in Recovering Industrial Landscapes: Effects of Landscape Degradation and Remediation Near an Abandoned Metal Smelter on Gypsy Moth (Lepidoptera: Lymantriidae) Feeding, Frass Production, and Frass Properties

摘要: Although insect defoliators are recognized as major agents of ecological change in North American forests, their ecology industrially degraded landscapes with poor-quality soils, metal contamination, and marginal vegetation growth is largely unknown. We fed gypsy moth larvae (Lymantria dispar L.) paper birch leaves (Betula papyrifera Marsh) (Fagales: Betulaceae) collected from four forested catchment areas near an abandoned Cu/Ni smelter Sudbury (Ontario, Canada) different histories industrial degradation remediation (reference, remediated, natural recovery, degraded). measured caterpillar feeding, frass properties decomposability, the effects on ticklegrass (Agrostis scabra Willd.) (Poales: Poaceae). Caterpillars generally ate more (+25-50%) produced (+30-40 %) a diet sites. Frass had overall positive effect plant survivorship (+4.1-10.8 size) (+0.1-0.5 size), although smallest benefits came derived heavily Our results suggest that defoliating insects respond to differences environmental may be particularly susceptible extensive defoliation increased conversion foliar biomass into frass, which could alter survivorship, soil development, nutrient cycling. Some these pose additional challenges landscape recovery (e.g., defoliation) while others beneficial enhanced development).