75 



" At the end of summer these watery, swollen growths dry up and die, and thus form 

 deep cracks. With the return of spring (as in other cases of injury) a new growth forms 

 round the dead part, and this soft tissue is ready for the young Aphides. Thus, from the 

 swollen diseased growth partly caused by the Aphides, partly by the natural attempts of 

 the tree to repair damage, a constantly increasing diseased mass arises, which shelters the 

 insects in its crevices and hnds food for them in its young hypertrophied formations." 



In America, on the other hand, this minute insect works under ground, and produces 

 upon the roots swellings and excrescences of all sorts of shapes and sizes. These materially 



interfere with the tree's supply of nourish- 

 ment, and when very numerous occasion its 

 death, especially if the tree be very young. 

 In Canada we are not aware that this insect 

 has been ever observed, though a similar 

 cotton-covered insect is very common on the 

 branches of the alder, nor does it prevail in 

 the more northerly parts of the Northern 

 States, but further south, especially in South- 

 ern Illinois and in Pennsylvania, it has been 

 regarded as one of the worst enemies against 

 which the apple trees have to contend. In 

 1848 it was found to be so abundant on the 

 roots of nurserv trees in Chester Countv, in 



, The swellings on the root ; b, the larva, with the 

 woolly matter attached to its back ; c, the perfect 

 winged insect. 



the latter State, that thousands of young trees had to be thrown away. In the Eastern 

 States it has frequently been found upon the branches of trees above ground, while work- 

 ing at the same time beneath the soil, and on the continent of Europe it has occasionally 

 been found under ground, producing the same swellings upon the root as in America. It 

 is evident, then, that the habits of the insect are governed by the nature of the climate 

 and the character of the soil. 



This insect, to quote Miss Ormerod's Manual, "may be known at a glance from the 

 common Apple Aphis {Aphis mali), which is injurious to the leaves, by the white wool 

 with which it is more or less covered, and from which it takes its name of 'Woolly 

 Aphis,'and an examination of the wings through a magnifying-glass will show that they are 

 differently veined. A strong vein runs down the fore wing near the front edge, and from 

 this three veins turn off towards the hinder edge. The tkird of these veins from the body 

 has only one fork in the American Blight or Woolly Aphis. By this the Schizoneurinoe, 

 to which division it belongs, are distinguished from the Aphidince, which have two forks 

 to this vein (as in the Hop Aphis) ; from the Pemphigince, which have this third vein 

 without a fork (as in Lettuce Aphis) ; and from Chermisince, in which this third vein is 

 absent (as in Larch Aphis and Spruce Aphis). This difference in the veins of the fore 

 wings is one clear distinction between the above-mentioned four tribes, of which the great 

 family of Aphididce (which includes all the various kinds commonly known as Aphides) 

 are composed. 



"The Woolly Aphides are without honey -tubes, and underneath the wool are mostly 

 of a yellowish, reddish, or reddish plum-colour. The winged specimens are described as 

 pitchy between the wings, and green, or with the abdomen of a chocolate-brown. The 

 wingless females may be found packed closely together in the cottony masses, Avdth the 

 pale reddish young moving about amongst them. Winged specimens may be found in 

 July and August." 



When attacking the roots, the easiest mode of getting rid of this insect is to drench 

 the infested locality with very hot water, which, though hot enough to destroy the life 

 of the insect, is not injurious to the vegetable organization. In the case of young trees 

 that are being transplanted the pest may be got rid of by dipping the roots in strong 

 soap-suds or tobacco water. 



When, however, as in England, the insect affects the branches, "its great harbouring 

 points and the nooks from which the broods come forth in spring and infest the trees, are 

 crevices, especially such as are formed of young bark sheltered under old dead masses. 

 It is, therefore, very important to keep up a clean, healthy, well-trimmed state of the 

 branches, such as will not allow of lurking places, or, if they do exist, will allow of these 



