Introduction: North African wadis, though rare and often temporary, play a vital ecological and socio-economic role in arid to semi-arid regions. These fragile ecosystems face multiple natural and anthropogenic pressures, including prolonged droughts, irregular flows, water overexploitation, pollution, and habitat degradation. This study aims to analyze the structure and dynamics of the Functional Feeding Groups (FFGs) of benthic insects to assess the ecological quality of four wadis located in the Aurès region (eastern Algeria) and to determine whether the functional patterns observed are comparable to those reported in streams from temperate and tropical regions.

Methods: Seasonal sampling was conducted from 2021 to 2022 across 48 stations.

Results: In total,19,431 benthic insects belonging to 7 orders, 37 families, and 59 taxa, classified into 7 FFGs, were detected. In the unimpacted wadis, the benthic assemblages were characterized by the presence of several IBMWP-sensitive families, including Ephemeroptera (Baetidae, Caenidae), Trichoptera (Hydropsychidae, Sericostomatidae), and Coleoptera, which correspond functionally to shredders, filtering collectors, scrapers, and predators. These taxa are typically associated with good ecological status and stable habitat conditions in IBMWP-based assessments.

In contrast, impacted wadis were largely dominated by pollution-tolerant Diptera, particularly Chironomidae and Dixidae, which are classified as low-score taxa in the IBMWP system and correspond functionally to gathering collectors. The marked reduction or absence of sensitive IBMWP taxa in these sites is fully consistent with the functional diversity observed in temperate and tropical regions. FFG ratio analyses revealed clear differences between impacted and unimpacted wadis, highlighting variations in autotrophy/heterotrophy balance, habitat stability, and trophic structure.

Conclusion: Overall, the Functional Feeding Group (FFG) indices observed in the study area were found to be comparable to those reported from temperate and tropical regions. These indices proved effective in distinguishing ecological conditions and can serve as reliable tools for the biomonitoring and management of wadis exposed to arid climatic constraints.