Average elemental body composition (by dry mass) of common O. mykiss and D. tenebrosus diet items* by order.

Elemental composition estimates from the literature for orders Lepidoptera and Hymenoptera did not include estimates of variability.Footnotes: *Unaccounted for percentage of diet was comprised of diet items not covered by invertebrate CNP survey and for which values could not be found in literature. Contributions by these uncommon items were deemed inconsequential due to their small individual proportion of the wet mass of diets. Large and/or unique diet items (orders comprising 1Frost PC, Tank SE, Turner MA, Elser JJ (2010) Elemental composition of littoral invertebrates from oligotrophic and eutrophic Canadian lakes. Journal of the North American Benthological Society 22:51–62.2Elser JJ (2003) Biological stoichiometry: a theoretical framework connecting ecosystem ecology, evolution, and biochemistry for application in astrobiology. International Journal of Astrobiology 2:185–193.3Woods HA, Fagan WF, and Elser JJ (2004) Allometric and phylogenetic variation in insect phosphorus content. Functional Ecology 18:103–108.4Elser JJ, Fagan FF, Denno RF, Dobberfuhl DR, Folarin A, Huberty A, Interlandi S, Kilham SS, McCauley E, Schulz KL, Siemann EH, Sterner RW (2000) Nutritional constraints in terrestrial and freshwater food-webs. Nature 408:578–580.5Slansky Jr. F, and Feeny P (1977). Stabilization of the rate of nitrogen accumulation by larvae of the cabbage butterfly on wild and cultivated food plants. Ecological Monographs 47:209–228.6Cross WF, Benstead JP, Rosemond AD, and Wallace JB (2003) Consumer-resource stoichiometry in detritus-based streams. Ecology Letters 6:721–732.