Page:The American Cyclopædia (1879) Volume XIII.djvu/494

 478 PHYLLOXERA in America, most of them inhabiting galls upon the leaves and twigs of different species of hickory (carya), one inhabiting the grape vine, and one only, on oak (phylloxera Rileyi}, he- ing an external feeder. None of these species except that on the grape vine seriously affect man's interests. In 1865 a disease of grape vines in the vineyards of France began to at- tract general attention. It was first noticed in the lower valley of the Rh6ne, a little above Avignon, upon the plateau of Pujault, depart- ment of Gard. In 1866 the disease had not only spread north of Avignon, but was ob- served at different localities in the S. part of ]f FIG. 1. Phylloxera, Type Eadicicola. Healthy root. &. Root on which the lice are working, showing the knots and swellings caused by their punctures, c. Root deserted by them, on which the rootlets have begun to decay, d d d. Lice on the larger roots, natural size. e. Female pupa, dorsal view. /. Winged female, dorsal view, greatly enlarged. the department of Bouches-du-Rh6ne. In 1867 it continued to spread and to gain in inten- sity, and in 1868 the whole of the country along the left bank of the Rh6ne, from its mouth to the environs of Donzere, was infect- ed. In 1869 the disease became still more alarming, the older seats enlarging and coa- lescing, and many new points of attack be- coming known in the departments of Herault and Var. It now attracted universal atten- tion, and investigation of it was stimulated by a large government reward for a remedy. It continued to spread, though with diminished virulence, and at the close of 1874 it occu- pied more or less the whole area of the lower Rhone from Valence to the mouth, and from Montpellier to Toulouse ; around Bordeaux, on the right bank of the Gironde ; around Cognac in the north, and Lyons in the east. The government offers a standing premium of 300,000 francs for an efficient remedy, and the national academy of science puts forth un- tiring efforts to study the disease in all its fea- tures. It has already been found in restricted localities in Spain, Portugal, Switzerland, Aus- tria, and Prussia, either on American vines or in neighborhoods where such vines have been planted. The authorities in most of these countries, as well as in Australia, have prohibited the importation of Ameri- can vines into unaffected districts. One of the most marked features of the disease is the rotting and wasting of the roots. In 1868 Prof. J. E. Planchon of Montpellier discovered the real cause in a minute plant louse working upon the root. This insect, though it had previously been described in its apterous form under three dif- ferent generic names, was finally re- ferred to its proper genus and named phylloxera vastatrix by Planchon. Since then the term phylloxera has acquired a somewhat broader meaning than it at first conveyed ; it now des- ignates not only the genus of insects, but the disease in question. In 1869 M. J. Lichtenstein of Montpellier first suggested that the phylloxera which was devastating the vineyards of France might be the same as a species described as pemphigus mtifolice by Dr. Fitch, and known to make galls on the leaf of the grape vine in Amer- ica. Following up this suggestion, Prof. 0. V. Riley of St. Louis estab- lished the specific identity of the two insects in 1870, not only by careful comparisons, but by showing that the gall-inhabiting insects hibernate on the roots, and there acquire all the char- acteristics of the root-inhabiting in- dividuals. This last fact was also in- dependently proved by European ob- servers during the same year, and the specific identity of the types inhabit- ing leaves and roots has since been thoroughly established by careful anatomical study as well as by experiments. In 1871 Prof. Riley dis- covered that the roots of vines in America are attacked by the insect in the same manner as are those of Europe. In the autumn of that year he announced this discovery, and, in the fourth entomological report of the state of Missouri, gave every reason to believe that the failure of the European vine (mtis vinifera), when planted in America east of the Rocky mountains, the partial failure of many hybrids with the European vinifera, and the deteriora- tion and death of many of the more tender-