Direct and indirect effects of Drosophila larvae on the growth of moulds

This paper describes the effect of Drosophila melanogaster larvae on the growth of moulds on various resources, both natural and artificial. The Drosophila larvae directly reduced mould cover whilst they were active in the resource, primarily by the mixing effect of their feeding motion. When the larvae pupated, the mould could recover and, in some cases, subsequently performed better on resources which had been modified ('conditioned') by the larvae. Therefore, although the short term direct effects of the larvae on the mould were always negative, the long term indirect effects could be negative, positive or neutral depending upon the type of resource concerned.