The occurrence of freshwater macroinvertebrates and water quality were evaluated in tributaries of the El Montoso Forest Reserve, located in the locality of Tres Puntas, Herrera Province, Panama. Sampling was conducted in November 2022 and March 2023 using D-frame nets, sieves, and manual collection techniques. A total of 28 families, 11 orders, and 3 classes were identified. The most representative orders were Megaloptera, Plecoptera, Coleoptera, and Trichoptera, with dominant families including Corydalidae (18.6%), Perlidae (17.9%), Polycentropodidae (8.7%), and Ptilodactylidae (8.0%). A higher occurrence of individuals was recorded during the dry season. The Shannon index indicated very high diversity (H' = 2.76), with higher values in the dry season than in the rainy season. The differences observed between seasons could be related to rainfall variation, which may indirectly affect habitat structure. During the rainy season, increased streamflow could cause physical disturbances that limit the persistence of certain organisms, whereas more stable conditions during the dry season may favor their establishment. The BMWP/PAN index yielded a value of 128, which, together with physicochemical parameters, indicates good water quality.
