Аннотация:SUMMARY 1. Macroinvertebrate colonization of artificial leaf packs of differing palatability to detritivores was measured in a low‐order stream. 2. The most palatable leaf types—alder and young beech—were colonized mainly by detritivores and consumed rapidly, so that species diversity on the substrate remained low. In the case of the less palatable old beech and paper ‘leaves’, however, colonization was slower but species diversity approached that of the surrounding benthos. 3. After 1 week, species diversity in paper ‘leaf packs was equivalent to that of the benthos, but species composition was dissimilar. 4. I argue that species diversity of a patch of stream bed may be inversely related to the abundance or palatability of a given food resource, and that this relationship is maintained by the instability of the stream bed habitat, precluding a long‐term community response to increased food availability. It may be, however, that the dispersal abilities of many aquatic insects allow a rapid response to the creation of novel habitats.