. Elm leaf curl and woolly apple aphid. 100 M28S. 238 MAIXE ,\I, EXPKRIMEXT ST\T:0X. IQI2. malformations the root form occurs in clustere 1 masses. The in- jury to the trees is due both to the sucking up and exhaustion of the vital plant juices and to the poisoning of the parts attacked, as indicated by the consequent abnormal growths. Fig. 430. The damage is particularly seri- ous in the case of nurser}^ stock and young trees and is less often impor- tant after the tree has once become well established and of some size. Where this insect is abundant all the roots of a young tree t
. Elm leaf curl and woolly apple aphid. 100 M28S. 238 MAIXE ,\I, EXPKRIMEXT ST\T:0X. IQI2. malformations the root form occurs in clustere 1 masses. The in- jury to the trees is due both to the sucking up and exhaustion of the vital plant juices and to the poisoning of the parts attacked, as indicated by the consequent abnormal growths. Fig. 430. The damage is particularly seri- ous in the case of nurser}^ stock and young trees and is less often impor- tant after the tree has once become well established and of some size. Where this insect is abundant all the roots of a young tree to the depth of a foot or so become clubbed and knotted by the gowth of hard fibrous enlarge- ments with the results in a year or two of the dy- ing of the rootlets and their ultimate decomposition with attendant disappearance of the galls and also of the lice, so that after this stage is reached the cause of the injury is often obscure. On the trunks the presence of the lice results in the roughen- ing of the bark or a granulated condition which is particularly noticeable about the collar and at the forks of branches or on the fresh growth around the scars caused by pruning, which latter is a favorite location. On the water shoots, they collect particularly in the axils of the leaves, often eventually causing them to fall, and on the tender growth of the stems. The damage above ground, though commonly insignificant, is useful. Fig. 439. Crown a'.id ri-jt 01 young apple tree, showing characteristic sweUings or galls prorlnced by the root lice. (From Al\;. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Patch, Edith M. (Edith Marion), 1876-. Orono : Maine Agricultural Experiment Station
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherorono, bookyear1912
