SYNCHRONIZATION WITH HOST-PLANT PHENOLOGY AND GALL SITE PREFERENCE OFDINIPPONAPHIS-AUTUMNA (HOMOPTERA, APHIDIDAE)

The distribution pattern of leaf galls induced by Dinipponaphis autumn a on its host plant, Distylium racemosum, was studied to clarify wheth er this aphid can select better galling sites in order to achieve its maximum fitness. The results demonstrated that this species cannot sel ect an optimal site for galling at the leaf position level, due to the short life-span of seem mothers under starved conditions and the rela tively shea period of time at which a leaf is suitable for galling. Th us, the galling position among leaves was determined by the synchroniz ation between the appearance of stem mothers and the leaf-opening phen ology. However, at leaf part level, the present study supported the pr eference-performance hypothesis, since stem mothers preferred the basa l intermediate part (B-part) of a leaf blade for galling. On this leaf pare, aphids produced larger galls containing more alates.