Studies of interactions among the leaf-top herbivores of Heliconia imbricata were undertaken in Costa Rica. One study consisted of monitoring the colonization of experimental patches of habitat (cacao leaves) to see if colonists preferred uninhabited patches. A second study involved placing various numbers of Cephaloleia consanguinea larvae under experimental patches, and monitoring their departure. Evidence for interference between colonist and resident individuals of some morphotypes and among C. consanguinea larvae at high densities was obtained. Neither experiment indicated that interference contributes significantly to guild structure among these herbivores.