4.3 Influence of season on the distribution of feeding types 
For two of the functionl feeding groups (FFG), we observed an influence of sampling time on the relative proportion of FFG, partly confirming our third hypothesis. Shredders showed a large increase from summer to winter and a decrease afterwards. As shredders feed on allochthonous material such as decomposed leaf litter, the increase of the relative proportion of shredders in winter is likely due to an increase in their food after fallen leaves accumulate in the stream (Cummins, 1974; Cummins et al., 1989). Although we expected to detect a higher number of grazers in the warmer months, we did not detect an effect of sampling day on the relative proportion of grazers. As the number of detected species was in general extremely low in the summer samples, the lack of seasonal effect on the proportion of grazers detected is likely the result of the extremely dry and warm summer in 2018 reducing the abundance of temperature sensitive taxa. Since we only looked at presence/absence data, it is possible that abundance data would have shown higher proportions of grazers in summer. Proportion of parasites was highest in summer and their occurrence was likely linked to their hosts. The exclusively parasitc larvae of Sisyra terminalis , which was frequently found in the spring and summer but not winter samples, is known to parasite on sponges and the species Spongilla lacustris and Eunapius fragilis , which were also present in our dataset, are known to form colonies during warm seasons and produce gemmules over the cold seasons (Gugel, 2001; Weißmair, 1994). Additionally, also the Trichoptera Ceraclea nigronervosa , which feeds on Spongillidae (Graf et al., 2002), was detected in the summer and spring month but not in the winter months, further encouraging the influence of the abundance of sponges on the detection of their hosts/predators. These results are promising for future eDNA based biomonitoring, as we could detect shifts in the relative proportion of different FFG and therefore changes in functional composition of the macroinvertebrate community over time, which could help to determine changes in ecosystem functioning (Minshall et al., 1992).