Several stream detritus feeders prefer to eat partly decomposed leaves
with a rich microbial population rather than sterile or freshly falle
n leaves. Leaves may already bear inoculum of typical aquatic hyphomyc
etes when they enter the streams, and are in many cases soon extensive
ly colonised by fungi. The food of leaf eating invertebrates actually
consists of two main components; leaf material and fungal mycelium. Ex
periments conducted to investigate how individual fungi influence the
palatability of leaves, demonstrate the influence of fungal population
on the leaves on food selection by stream invertebrates, thereby pote
ntially controlling and directing the turnover of leaf detritus.