Liriomyza avicenniae Martinez sp. n., from Guadeloupe and Saint-Martin, and Phytoliriomyza cyatheana Étienne sp. n., from Guadeloupe and Martinique, are described and illustrated on males and females specimens respectively obtained from leaves of Avicennia germinans and leaves of two tree-ferns: Cyathea (Cnemidaria) grandifolia and Cyathea (Cyathea) arborea. A table mentioning all the Phytoliriomyza living on ferns is given. (Refdoc)