Longitudinal zonation of larval Hydropsyche (Trichoptera: Hydropsychidae): abiotic environmental factors and biotic interactions behind the downstream sequence of Central European species

Abstract The aim of this review is to summarize the literature knowledge about how abiotic environmental factors and biotic interactions affect sequentially overlapping longitudinal distribution Central European species net-spinning freshwater caddisfly larvae genus Hydropsyche (Trichoptera: Hydropsychidae). In relation, several physical chemical parameters water are discussed, as well different species-specific traits, behavioural aspects interaction coexisting species. Longitudinal gradients river networks, especially annual temperature range, flow velocity particle size suspended food material play a crucial role in forming downstream succession characteristic species, while increased levels organic pollution, nutrients, salinity heavy metals facilitates presence more tolerant ones. Several such respiration net-building frequency, head capsule or optimal correlate with position given sequence. Coexistence similar ecological demands zones facilitated by differences feeding habits, microhabitat preferences staggering life cycles, but complicated at same time means inter- intraspecific territorial behaviour, fighting for ownership larval retreats practice stridulation.