Anatomical alterations induced by Meloidodera mexicana and Meloidodera sp. were studied in roots of chili pepper and hawthorne, respectively. Swollen females of M. mexicana protruded with the posterior portion of the body from the surface of chili pepper roots, whereas Meloidodera sp. females remained inside the root tissues of hawthorne. Swollen females of both species were surrounded by a capsule in collapsed cortical parenchyma cells and the shed cuticles of the third and fourth-stage juveniles. Meloidodera mexicana and Meloidodera sp. fed on stele tissue which induced the formation of a mononucleate giant cell originating from a vascular parenchyma cell. Giant cells had dense cytoplasm, numerous vacuoles, and an hypertrophied and amorphous nucleous. Cell wall thickening was observed near the site of stylet penetration. The cells near the giant cells induced by Meloidodera sp. exhibited hyperplasia.
