Dynamic microhabitat shifts in space and time of caddisfly larvae (Insecta: Trichoptera) in a first‐order calcareous mountain stream

Abstract By studying substrate (choriotope) preferences of 25 caddisfly taxa in the Schreierbach stream, a calcareous, first order tributary Ybbs river (Lower Austria), we aimed on (1) detecting microhabitat space and time, (2) to relate this information with ontogenetic choriotope shifts, (3) explore relationships between feeding guilds choriotopes chosen. For this, took six sets bi-monthly multi-habitat samples larvae at three stream sections (360 samples). Densities were highest Drusinae juveniles (53.60 %), Micrasema morosum (15.14 Drusus discolor (13.31 %) D. monticola (4.46 significantly higher upper section (1900 ± 1039 m − 2 ) than central (205 23) lower (141 22). Ivlev electivity indices revealed for Macrolithal Rhyacophila spp. Tinodes dives , Microlithal juveniles, Megalithal Phytal filtering Xylal Akal Limnephilinae. A cluster analysis yielded five clusters, corresponding functional types. At instar level, chosen grain size increased increasing some species. Observed habitat shifts time reflected interaction instar-specific choice longitudinal translocations.