Eastern hemlock (Tsuga canadensis) is being damaged and killed by an exotic insect pest, the hemlock woolly adelgid (HWA), Adelges tsugae. As slow-growing, shade-tolerant trees, hemlocks can be an important part of the riparian vegetation in eastern forest streams. The full impact of HWA on hemlock-associated ecosystems, especially streams, is unknown. The purpose of this study was to examine the role of riparian hemlock, using a gradient of hemlock cover to simulate hemlock decline due to HWA. In 2005, benthic macroinvertebrates were collected seasonally from six stream sites in Giles Co., Virginia. In 2006, hemlock needles were placed in streams and collected over time to evaluate litter breakdown rates. Low-density hemlock streams averaged fewer shredder macroinvertebrates (10% total organisms) compared to 50% shredders at the high-density site. Scrapers were more abundant in low hemlock density streams. Other functional feeding groups showed little to no difference along the hemlock cover gradient. Hemlock litter had a slow to medium breakdown rate (k=0.006, r² = 0.89) across all stream sites. These results suggest that decline and loss of hemlock due to HWA may result in a subtle shift in macroinvertebrate assemblage structure and loss of a long-lasting litter source in hemlock streams.