Abstract
In recent years, there has been a growing interest in understand- ing the ecological importance of ecosystem engineers. In this paper we argue that parasites, through the phenotypic alter- ations they induce in their hosts, are likely to be involved in engineering processes for at least two reasons. First, when ecosystem engineers are themselves infected, phenotypic alterations induced by parasites can interfere with host traits involved in the engineering processes. Secondly, parasites themselves can be ecosystem engineers since the phenotypic alterations of hosts directly modify the habitat of all the species inhabiting free-living organisms. This new research area at the interface between ecology and parasitology should improve our understanding of the ecological cdnsequences of phenotypic alterations induced by parasites in ecosystems.