A. M. Taylor 247 



In both cases, reproduction, although apparently stimulated at 

 certain seasons and checked at others, continues throughout the year. 



Superficially the injury to their host by both mite and worm is 

 identical, that is, the destruction of the buds and the diversion of the 

 growth resulting in the loss of vitality to the tree are constant in both 

 diseases. There is however a difference in the degree in which these 

 symptoms occur. 



Points of dissimilarity. No abnormal growth of the bud occurs 

 as the result of an eelworm attack. Big buds, though worms may 

 be present in them, are due to the action of mites alone. 



A distinction is seen in the appearance of the bud leaves attacked 

 by the two pests. Those recently invaded by worm shew, where colonies 

 have become established, isolated discoloured areas which become 

 confluent as the disease progresses. Accompanying this discoloration 

 is a conspicuous state of moisture in which the diseased portions 

 assume a transparent appearance. Such buds are incapable of further 

 development. 



These symptoms maintain in the buds successively attacked 

 throughout the year. 



Such discoloration does not occur throughout the year in the mite 

 attacked buds. A certain darkening of the tissues may occur in iso- 

 lated cases during the autumn months, following which discoloration 

 is general among doomed buds. There is, however, an opaque appear- 

 ance of the dying tissues, and the state of moisture is entirely absent. 



An essential difference occurs between the migrations of the two 

 pests. The worms, by reason of their comparatively rapid disintegrat- 

 ing action on the tissues of the bud, are forced to migrate at frequent 

 intervals as the buds die throughout the year. The mites however 

 migrate definitely in the spring of the year, and with the exception 

 of quite minor migrations (which apparently occur among individuals 

 throughout the summer and autumn months) stay within the buds 

 they enter, until the following spring. 



The action of the mites on the leaf tissue is not one of disintegration, 

 but is essentially stimulating. It causes the bud leaves to increase 

 perceptibly and the whole bud to enlarge. 



Such briefly are the main points of distinction between the two 

 pests, and it now remains to consider the biology of the nematode in 

 detail. 



Life history. It has been seen that the worms enter the buds, 

 with the brief exception alluded to, at all seasons of the year. That 



