The Distribution and Island Endemism of Hawaiian Delphacidae (Homoptera) with Additional Lists of Their Food Plants.

In presenting the following tables as a guide and check list to such as may be interested in this group of our endemic leaf-hoppers, the compiler wishes to digress somewhat from the introductory remarks which such tables might ordinarily occa sion. Because our endemic leaf-hoppers, like some others else where, do not particularly affect agricultural interests, and therefore are of no special economic importance, some may wonder why so much interest is taken in their biology and morphology by our local entomologists. There are several rea sons for this. First, because of several very injurious species of hoppers, not so very far from our gates, which as yet have not reached Hawaii; and, second, because the sugar cane leaf-hopper (Perkinsiella saccharicida), which cost this Territory losses of many millions of dollars in 1903, 1904 and subsequent years, is, as it were, the foundation-stone of economic entomol ogy in Hawaii. Not only was this Delphacid responsible for large money losses, but it was also the cause for organizing in 1903 of a large staff of entomologists for biological research and field work in the Territory, and the building up of such organizations as the Experimental Station of the Hawaiian Sugar Planters ' Association and the Territorial Board of Agri culture and Forestry and its Plant Quarantine and Inspection Department. It is therefore not surprising that the many families and groups of leaf-hoppers distributed through both continents are of more than passing interest to some of our systematic as well as economic workers. The systematic study of these families or groups, whether local or foreign, is quite necessary because, with Hawaii as the "Cross Roads of the Pacific " and in almost daily steamship communication with many tropical or sub-tropical regions, there is always the pos sibility that one or more of several known species of hopper