Root Galls

Abstract

The study of root galls and the root gall communities belongs properly to the field of soil biology. The ecology of root galls is complicated by the fact that among the organisms, which induce galls on the roots of diverse plants, there are in addition to the strictly edaphon, many species of the aerial habitat, which have an edaphic phase in their life-cycle and cause galls during this phase. Some of the aerial species give rise to galls on roots in successive generations, but others give rise to galls on roots in alternate generations only and on different aerial organs in alternate generations by turn. Some of the outstanding features of the structure, development and ecology of root galls may be traced to these peculiarities. The edaphon that cause root galls include bacteria, fungi and Nematoda. To the second ecologic group belong aphids, Curculionidae, Buprestidae, Itonididae and certain species of Cynipidae with heterogony. Groups of cecidozoa like Acarina and Thysanoptera are excluded from the root gall community. Unlike in the case of aerial galls, it is only exception that the gall-maker is found externally on the surface of the galled root.