The Effect of the Gall-Forming Aphid Schlechtendalia chinensis (Hemiptera: Aphididae) on Leaf Wing Ontogenesis in Rhus chinensis (Sapindales: Anacardiaceae)

Abstract

Abstract The aphid Schlechtendalia chinensis (Bell) induces large single-chamber galls, called horned galls, on the leaf wings (an extending part of the rachis) of Rhus chinensis Miller. Horned galls are initiated when the fundatrix of S. chinensis feeds on the adaxial surface of the leaf wings. We compared the histology of intact versus galled leaf wings during various developmental stages by observing their histomorphology during their chronological development. We found that at the initiation phase, the outer epidermis and opening zone of the galls had many glandular trichomes and that pallisade tissue was replaced by parenchyma cells. The number of glandular trichomes on the outer epidermis was reduced as galls matured. The latex ducts and vascular elements became denser in the inner gall layer, and closer to the gall cavity. Stomata were found on outer epidermis in all gall developmental stages excluding the initiation phase. The effect of the gall-forming aphid on leaf wing ontogenesis is discussed.