Herbivores and detritivores'species that consume decaying material'are ecologically linked through their participation in nutrient cycling and shared consumption of plant tissue. Herbivores can influence the quality of plant litter available to detritivores by feeding on living plants and inducing plant defensive responses. We typically assume that detritivores respond to these herbivory-induced differences in litter quality in the same way that they respond to other differences in litter quality. However, herbivore-induced changes in litter chemistry might influence detritivore litter processing differently than other changes in litter quality. I tested the impact of herbivory history on detritivore litter consumption and the transfer of those nutrients back into plant biomass in old-field experimental mesocosms. I added leaf litter with a factorial legacy of grasshopper herbivory and nitrogen fertilization to mesocosms with different densities of a common detritivorous woodlouse. After a growing season, I quantified differences in plant, microbial, and woodlouse biomass across the litter history x woodlouse treatments. The differences in litter quality across herbivory and fertilization treatments interacted with woodlouse abundance to influence total plant biomass at the end of the growing season. Woodlice decreased plant biomass when litter had a history of herbivory, but had no effect on plant biomass when litter was not fed on by herbivores. The opposite trend was observed for microbial biomass. Woodlice decreased microbial biomass when litter had no past herbivory. The woodlice consumed fertilized plant litter more than unfertilized plant litter and the liberation of nutrients from fertilized litter resulted in a grass-dominated plant community. My results provide a novel demonstration of strong feedbacks between herbivores and detritivores under field conditions. They also suggest that differential detritivore litter processing might modify the longer-term effects of herbivores on plant litter quality and plant communities.