Following an up-to-date synopsis on the planthopper fauna and their associated host-plants in the Mascarene Islands including numerous new data, a study of host plant and Fulgoromorpha interaction patterns illustrates some remarkable specificities. The endemic fauna remains essentially on endemic plants and exotic planthoppers have not shifted to them, remaining on exotic plants. Two fulgoromorph families are strictly associated with monocotyledons: (1) the Delphacidae represented by widespread species maintain the same host as the continental source populations, especially exotic Poaceae and (2) the Derbidae which displayed a food conservatism for woody plants are found mostly on endemic Arecaceae, Pandanaceae and Liliaceae. These relationships differ from continental Derbidae, which are recorded as much on dicotyledons as on monocotyledons. Other island specificity appears with the endemic species of Meenoplidae from La Reunion, which are recorded on endemic dicotyledons whereas the continental species are recorded on monocotyledons. In La Reunion, a positive correlation between endemic planthopper diversity recorded on different host plants and endemic plant diversity within different plant orders was observed. This result suggests a stochastic distribution of the planthoppers on the available botanical taxa at the time of colonization. In the Mascarenes, disparities appear between Cixiidae from La Reunion and Mauritius. On the latter, the Cixiidae seem to be mainly monophagous and the majority of them are recorded on Rubiaceae. [ABSTRACT FROM AUTHOR]