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LiNDiNGER (L.) Tatigkeitsbericht der Schadlingsabteilung des 

 Instituts fiir angewandte Botanik zu Hamburg fur die Zeit vom 

 14 Februar bis zum 30 Juni 1920. [Report of the Pest Division 

 of the Jiamburg Institute for Applied Botany for the Period 14tli 

 February-30th June 1920.] — Zeiischr. angeiv. Ent., Berlin, vii, 

 no. 2, February 1921, pp. 424-440. 



One section of this report deals with the original habitat of, and 

 measures against, the vine louse [Phylloxera vastairix]. The author 

 is of opinion that there is no evidence to justify the popular idea that 

 North America is the original home of this pest. The home of Vitis 

 vinifera is known to some extent, but little information is available 

 regarding the pests of wild vines. The author has investigated the 

 Coccids found on Vitis vinifera cultivated in the Old World, as regards 

 their country of origin and their infestation of other plants. Of these, 

 the only one that seems to throw any light on the question is Targionia 

 vitis, which occurs on Arbutus, Quercus arid Vitis. In connection 

 with the oak-infesting species of Phylloxera the author is inclined 

 to connect the home of both P. vastatrix and the vine with that of 

 the European-Mediterranean species of Quercus. The occurrence of 

 T. vitis on Arbutus indicates the south of this region. The vine grows 

 wild on the shores of the Black Sea, and the author believes that 

 region to be the original habitat of P. vastatrix. He thinks that 

 P. vastatrix and the species infesting oak belong to the same genus. 

 The fact that P. vastatrix has been found on the vine only does not 

 prevent it from being a migratory species, in the development of 

 which a species of Quercus plays a role. Consideration of the Coccid 

 fauna tends to support this view, and it is highly desirable that the 

 pests of wild vines and of plants allied to them should be ascertained 

 in various places. One such locality is the Bulgarian forest called 

 Deliorman, on the Rustchuk-Schumen line. 



Attention is also drawn to the fact that the distribution of Phylloxera 

 in the Caucasus points to its probable place of origin being in that region, 

 where the increasing clearing of forests and la3dng-out of vineyards 

 brings the vine nearer to the forests and increases the possibility of 

 infestation. 



The section dealing with remedial measures refers solely to the use 

 of American stocks. These are preferred on account of their vigorous 

 growth and greater immunity. In recent years, however, cases of 

 severe infestation have occurred on them. The author believes the 

 less vigorous growth of cultivated vines to be due to artificial propa- 

 gation during thousands of years. Sufficient attention has not been 

 given to the fact that on certain soils — such as some Hungarian sandy 

 soils — Vitis vinifera remains uninfested. This is not to be ascribed 

 to any chemical property of the soil, but simply to the fact that the 

 roots are able to go down to a considerable depth. Like all Rhynchota, 

 P. vastatrix requires a certain amount of air, and therefore lives near 

 the surface. If the roots are able to reach a safe depth before sus- 

 taining severe injury, they are able to escape the parasite higher up 

 by developing a stout bark. If a subsoil layer of slate, etc., is present, 

 the roots are forced to spread out near the surface, and the vine is 

 helpless against infestation. The author agrees with the observations 

 of Popoff and Joakimoff [R.A.E., A, v, 533], though he advises that 

 vines should be trained in an horizontal direction at not too great 

 a height. 



