Responses of the Host Plant Tissues to Gall Induction in Aspidosperma spruceanum Müell. Arg. (Apocynaceae)

The ontogenetic characterization of the leaf galls induced in the internervural region and in the second and third order veins of A. spruceanum Müell Arg. (Apocynaceae) aims to evaluate the distinct levels of cell reaction during the process of gall formation, and the relation between external gall morphology and the oviposition sites. The ground system had the most remarkable alterations, namely, the non differentiation of palisade parenchyma in both leaf sides, the hyperplasia of the spongy parenchyma and the neoformation of fibersclereids, a cell type not observed in non galled leaves. Changes of the feeding sites inside the larval chamber reveal distinct levels of cell competence to respond to the insects stimuli and explain the variations in the shape of the larval chamber.