Attracted by exudates released by the coffee roots, J2 nematode (migratory stage) moves toward to food source. The nematodes penetrate in the roots and search for a site to feed on. Several cells are selected to start uptaking food. Those cells are modified and grow bigger (hypertrophy) without cellular division. However, nuclei division start happening and many nuclei are produced inside generating giant cells. Surrounding cells will suffer hyperplasia and start cellular division wildly. For "M. exigua", these cells will become galls, but not for "M. coffeicola".