APPLE BLIGHT. 183 



Last August, the stalks of an elder shrub in our garden were 

 absolutely blackened at the joints by Elder Aphides, and 

 among these were continually to be seen a multitude of brown 

 Ants, demanding and receiving their supplies of honey-dew 

 as emitted by the former. 



Besides the general analogy which exists between flocks of 

 Aphides and flocks of sheep, in their gentle nature, their gre- 

 garious habits, and in their being appropriated so extensively 

 for food, there may be noticed, in several instances, a curious 

 kind of external rapport between them and the woolly-coated 

 quadrupeds. 



There are some species of Aphides which are actually 

 clothed with a sort of wool or down. One of them, a four- 

 winged Gall insect,* is found in June or July on the poplar, 

 or may be often noticed at that season, flying or floating 

 about in the air, like a small white tuft of down. Another 

 hoary-coated Aphis is unfortunately too well known to apple- 

 growers under the name of " "White Blight." The branches of 

 those trees selected for their pasture by our insect sheep, are 

 soon invested by their numerous fleeces with a hoary aspect, 

 appearing in spring and increasing through the summer. 

 These fleeces are found upon examination to consist of a woolly 

 or cottony substance, exuded from the insect's bodies, and 

 under its cover a multitude of these wingless Aphides are 

 incessantly at work with their destructive pipes, sucking up 



* Eriosoma populi. 



