Anthropogenic landscapes change the functional feeding group diversity of aquatic insects in streams of the eastern Amazon

The study of functional feeding groups (FFGs) is essential for understanding stream ecosystem functioning, as these groups can be affected by environmental changes that alter ecological processes. We evaluated the effects of different land-use types and a Habitat Integrity Index (HII) on the relative abundance of FFGs of Ephemeroptera, Plecoptera, and Trichoptera in 32 streams in the eastern Amazon in October 2022 and March 2023. Using generalized linear models and Threshold Indicator Taxa Analysis, we found that HII was positively associated with the proportion of shredders and negatively associated with the proportion of scrapers. Gatherer-collectors responded positively to increases in habitat integrity, whereas filter-feeders and predators showed no responses along this gradient. All FFGs responded individually to other landscape metrics. Shredders and gatherer-collectors emerged as bioindicators of HII gradients. At the genus level, Cernotina , Macronema , Miroculis , and Phylloicus responded to HII, while Leptonema responded to forest cover. Our results demonstrate that habitat integrity loss and anthropogenic landscapes affect both the composition and relative abundance of FFGs in aquatic insect communities, highlighting the importance of conserving riparian vegetation to maintain ecosystem functionality and biodiversity. Furthermore, the use of FFGs as bioindicators is a powerful approach for assessing the impacts of environmental change on ecological interactions and processes, suggesting that future research should investigate the specific responses of FFGs to different management practices over time. • Habitat integrity increases shredder and gatherer-collector abundance in Amazonian streams. • Scraper abundance also increases with habitat integrity, contrary to predictions. • Filter-feeders decline with industrial land use; predators remain stable • Specific EPT genera indicate higher habitat integrity in Amazonian streams. • Functional feeding groups are effective bioindicators of stream ecosystem health.