Norton and Didham (1) argue that differences in plant abundance between tropical and temperate forests may limit the general conclusion that herbivore diversity scales directly with host plant diversity. They point out that our study (2) did not include locally rare tree species. Our temperate/tropical comparison was standardized for sample size and plant phylogeny but not for plant abundance a...

Plant resistance to herbivores was induced in a field experiment to evaluate the consequences of induced responses for subsequent herbivory and plant fitness. Induction early in the season resulted in halving of herbivory by chewing herbivores and a reduction in the abundance of phloem-feeding aphids when compared with controls. A correlate of lifetime plant fitness, seed mass, was enhanced by ...