Factors' governing ingestion by the earthworm Lumbricus terrestris (L.), with special reference to apple leaves

Captive worms fed little on fresh apple leaves, but did so readily after the leaves had been leached in water. This was due to their being soft and easy to fragment and not to loss of unpalatable substances during the leaching process. A simple apparatus to measure leaf texture is described. Worm feeding rates were similar for leaves of similar texture but of different phenolic content. Filter paper was accepted as food. The addition of leaf leachates to filter paper disks increased feeding rates, so did added bacterial cells. The part played by leaf micro-organisms in the nutrition of worms and their effect on leaf texture is discussed. Unsoftened leaf material was readily eaten provided it was small enough to be swallowed whole. Leaves from various aromatic plants were eaten by starved worms, but rejected by well-fed ones. Starved worms given aromatic leaf material together with apple leaf preferred the latter. Various unusual materials were eaten, but polyester foam was accepted only when coated with bacterial cells. Responses to chemical as well as to tactile stimuli seem to be involved.