Didymosphenia geminata (didymo) mats alter the biotic diversity and distribution of freshwater invertebrates, including the reduction of diversity and abundances of mayflies, stoneflies, and caddisflies. However, some macroinvertebrates have increased presence in didymo impacted streams, including oligochaete worms and non-biting midges (chironomids). Interestingly, only chironomids of the sub-family Orthocladiinae seem to experience this increase in abundance, aided by their consumption and/or tolerance of didymo. This transition to consuming didymo may wear the teeth of larval chironomid feeding structures due to the larger size of didymo’s frustules (siliceous shells) and potentially impairs their ability to process other food items. This study examined 1) the differences in genera level diversity of larval chironomids in streams impacted by didymo, 2) the contributions of didymo frustules to their diet, and 3) the impact of dietary changes to the wear of menta. Our results suggest that only a few taxa comprise most chironomids in didymo impacted streams, and those genera consume didymo frustules. Mentum wearing was most prevalent in chironomid taxa which consumed didymo cells. These results suggest that utilizing this new food source may result in excessive wear of their feeding structures, but the tradeoff of utilizing the newly dominant food resource appears to outweigh this physical damage.