When insects emerge from streams and lakes, they provide energy subsidies to terrestrial food webs. As a result, subsidy theory largely assumes that the response of terrestrial predators is driven by the quantity of the subsidy (i.e. emerging insects). But emerging insects are more than a “quick meal.” Some may also be toxic, containing metals like mercury, zinc, and cadmium. Their toxicity is determined by a suite of factors: metamorphosis, species, metal bioavailability, geologic history. We study how these factors influence the trophic transfer of metals from stream to terrestrial food webs.