Plant-insect-fungus association in some plant galls
In a number of plant galls caused by members of Diptera, the larval cavity and/or the nutritive zone around it are inhabited by specific fungi. Careful investigations reveal that these fungi are not contaminants, but are brought by the gall insect itself. The fungi appear to lead a mutualistic life not only with the insect larva but also with the plant. Details regarding the fungi, and the nature of this three-way relationship, although fragmentary, are summarised, along with the author’s unpublished observations.