Abstract
Summary and graphs of results of quantitative analyses of fore-gut contents of 2 to 4 - weekly collections from 3 ponds and 3 streams of several sizes of larvae over 18 months. Main food component was detritus; algae, vascular plant tissue and mineral particles were also present. In correlation with physiological properties of both species, food consumption by C. dipterum showed marked decrease at low temperatures, while that of B. rhodani remained between 3 and 4 times as high. Composition of diet was related to both habitat and larval size. Differences in mean size between populations of B. rhodani were not correlated with differences in diet.