Every 13 and 17 years, billions of periodical cicadas (Magicicada spp.; hereafter cicadas) emerge from subterranean burrows, delivering a substantial pulse of biomass and nutrients that alters ecosystem structure and function across landscapes. Despite the magnitude of these events, critical gaps remain in our understanding of how freshwater ecosystems are affected by cicada emergences, particularly related to the magnitude and composition of cicada-derived subsidies entering streams. Our objectives were to provide a foundation for future research by: 1) estimating the density and biomass of cicadas drifting in streams, and 2) characterizing the taxonomic composition and sex ratios of cicadas entering streams. We counted individuals from three cicada species groups (Magicicada -decim, M. -cassini, and M. -decula). During the dual emergence of Broods XIX and XIII in 2024 across Arkansas, Missouri, Illinois, and Iowa, and later Brood XIV in 2025 across Tennessee, Kentucky, and Ohio, we deployed drift nets (26 x 45 cm) for 30–60 minutes in different streams for a total of 88 streams. Cicadas were present in the drift at 88% of sites, ranging from 0 to 79 individuals per deployment. Preliminary analyses indicate that drift densities ranged from zero to 45 cicadas·h-1 and biomass inputs from zero to 5.43 g·h-1. These estimates are likely conservative, as they do not account for cicadas consumed by aquatic macroorganisms prior to reaching the drift nets. Concurrent studies of fish foraging behaviors in a subset of these streams suggests that a substantial fraction of drifting cicadas are intercepted by fish and other macroconsumers. Of cicadas collected from the drift, approximately 50% were male, 35% female, and 15% undeterminable. Approximately 40% were identified as M. -cassini, 18% as M. -decula, and 6% as M. -decim, with 36% unidentifiable. By quantifying not only the magnitude of cicada inputs but also their species composition and sex-specific contributions, this study provides the first broad-scale assessment of periodical cicada subsidies entering lotic ecosystems. These datasets establish a critical baseline for evaluating how rare, pulsed terrestrial resource events influence aquatic food webs, nutrient cycling, and consumer dynamics across spatial and temporal scales.