Leaf-miners associated with common cultivated plants are especially liable to become esrahlished in new areas through transportation with their hosts, and this possibility should always be considered when the agrommyzids of poorly-known faunal regions are studied, so that redescription of such species as new forms may he avoided. One of the species here recorded for thc first time from both Chile and Easter Island is a case in point. Phytobia maculosa (Malloch), known as a leaf-miner in cultivated Chrysanthemum in the U.S.A. since 1896 (though not correctly recognized and described until 1913), has since been redescribed from the same host plant in southern Brazil. Its known hosts now include 13 genera of Compositae and it is evidently widespread in the U.S.A., in the West Indies, and in temperate South America. It also occurs in Hawaii. Although not so far reported in Canada it almost certainly will be found in southern Ontario and British Columbia. Horticulture, both private and commercial, must have greatly assisted its spread in North America and elsewhere.