In a series of 4 experiments conducted over 4 years, natural lotic macroinvertebrate communities were colonized by placing baskets of large gravel in a riffle in the upper Cache La Poudre River, Colorado and leaving the baskets in place for 30-40 days. The communities were then exposed in experimental streams to different combinations of five metals (cadmium (Cd), cobalt (Co), copper (Cu), nickel (Ni), and zinc (Zn). The metals exposures and associated counts of larval insects and other invertebrates remaining in the experimental streams are detailed in Child Items 1-4 of this Data Release. In this dataset (child item #5), we report the associated adult insect counts by day that successfully metamorphosed during the exposures, emerged, and were captured from nets covering the streams. Emergent adults were aspirated daily from nets covering each experimental stream. Adults were sexed and identified to genus except for Chironomidae, which were identified to subfamily or tribe.