The effects of potential larval supply, settlement and post-settlement processes on the distribution of two species of filter-feeding caddisflies

Abstract

1. Hydropsychid caddisfly larvae are often abundant in fast flow habitats and on highly textured substrata. Such patterns are usually inferred to result from habitat preference, but the roles of larval supply to the benthos and post-settlement events are rarely examined for stream populations. We describe a manipulative field experiment that examined larval supply, habitat preference and post-settlement events simultaneously for two co-occurring species of hydropsychids. 2. Ten artificial channels were constructed in a natural riffle to create fast and slow flow habitats and within each channel we placed six artificial substrata whose surfaces had been modified to create three different text..