Leaf litter quality drives the feeding by invertebrate shredders in tropical streams.

Amazon and Cerrado-forested streams show natural fluctuations in leaf litter quantity along the time and space, suggesting a change on litter quality input. These natural fluctuations of leaf litter have repercussion on the organic matter cycling and consequently effects on leaf decomposition in forested streams. The effects of the quantity of leaf litter with contrasting traits on consumption by larvae of shredder insects from biomes with different organic matter dynamics have still been an understudied question. The Trichoptera spp. is a typical shredder in tropical headwater streams and keep an important role in leaf litter decomposition. Here, we assessed the consumption by shredder spp., from Amazonia and Cerrado biomes, on higher () and lower quality leaves () in different proportions and quantities. Experiments were performed concomitantly in microcosms approaches, simulating Cerrado and Amazonian streams. Higher leaf consumption occurred in Cerrado microcosms. Litter quantity influenced negatively leaf consumption by shredders in Cerrado, in opposition to Amazonia, where consumption was not affected by leaf quantity. In both sites, we observed higher consumption by shredders in treatment with only and no difference between other treatments with mixture of leaves. In treatment with litter of we noted the use of substrate for case building (due to the higher leaf toughness) affecting the fragmentation process. Therefore, our results indicate that leaf litter quality drives the preference of consumption by larvae in Cerrado and Amazonia streams.