Spatial and temporal patterns in caddisfly (Trichoptera) distribution along the Breitenbach (Germany) 1983-1991

Sixtyeight caddisfly species have been collected in emergence traps along the Breitenbach since 1969. Four traps of equal size have been operated since 1983 along the lower 2 km of the stream. The most abundant species showed extreme variations in numbers between years and traps along the stream. A comparison of the number of specimens recorded from a single trap with the total number of specimens recovered per year from all traps, however, reveals clear and repetitive patterns of along stream distribution of individual species. Analysis of the variation patterns among species provided initial information about the grouping of taxa