Gall insect-host plant relationships—An ecological perspective
Compared to other phytophagous insects, the gall insects are specialised in view of their imperative demand for a particular type of food in terms of a specific host; this is further supported by their specialised trends in establishing a coordinated, functionally efficient system involving (i) the biogenesis of the host plant organ, and (ii) the life-cycle of the gall-maker. The ’inherent potential’ (genetic-?) of the gall-insect to establish an independent, yet a discrete habitat, modifying the host plant tissue to enjoy a self-contained nutritional guild, facilitated by the host selection patterns, appears especially different from the other non-cecidogenous phytophages.
Besides the autecological factors such as the changing climate, chemical and physical changes in the host tissue, and patchyness of food plant resources, which are of great importance to the cecidogens, of particular significance are the community interactions within gall systems involving many arthropod participants like inquilines, parasites, predators, and other casual visitors. As specialised organisms and with limited population size per unit area, the gall insects seem to run the risk of random extinction, although their efficient development of strategies to survive appears significant.