Abstract
The distribution pattern of leaf galls induced by Dinipponaphis autumna on its host plant, Distylium racenosum, was studied to clarify whether this aphid can select better galling sites in order to achieve its maximum fitness. The results demonstrated that this species cannot select an optimal site for galling at the leaf position level, due to the short life-span of stem mothers under starved conditions and the relatively short period of time at which a leaf is suitable for galling. Thus, the galling position among leaves was determined by the synchronization between the appearance of stem mothers and the leaf-opening phenology. However, at leaf part level, the present study supported the preference-performance hypothesis, since stem mothers preferred the basal intermediate part (B-part) of a leaf blade for galling. On this leaf part, aphids produced larger galls containing more alates.
