INSECTS INFESTING FRUIT TREES. 



1. THE APPLE. 



AFFECTING THE ROOT. 



Wart-like excrescences growing upon the roots, sometimes of an enormous 

 size; containing in their crevices exceedingly minute lice, often ac- 

 companied with larger winged ones having their bodies covered with 

 a white cotton-like matter. 



The Apple-root Blight, Pemphigus Pyri. Synonyms, Eriosoma Pyri, 

 Fitch, Fourth Report of the N. Y. State Cabinet of Nat. Hist., A. D. 

 1851, (Senate Document, No. 30) p. 68. Pemphigus dmericanus 1 

 Walker, List of Homopterous Insects in the British Museum, 1852, 

 p. 1057. 



Upon the 29th day of October, 1849, 1 was occupied in setting 

 out a number of young Apple trees which had been brought me 

 from the nursery at Glens Falls, Warren county, when, on the 

 roots of one of these trees, I observed some very singular excres- 

 cences. I was conjecturing as to the cause of this remarkable 

 disease, which appeared to be sufficient to destroy the tree, when, 

 nearly concealed in one of the largest excrescences, a woolly Plant- 

 louse was perceived, and on further inspection, a second one was 

 found, similarly secreted — one of these being dead, the other 

 alive. And on examining the crevices of this excrescence with a 

 magnifying glass, they were discovered to be occupied by nu- 

 merous lice, so minute as to be wholly imperceptible to the naked 

 eye. These, there can scarcely be a doubt, were the young of 

 the larger winged lice, first noticed. 



Upon the wing, ingioves, late in the autumn, I have captured 

 numerous individuals of this same species, where no apple trees 

 were growing within a half mile. These were probably bred 

 upon the roots of the Thorn or the Shad-bush (Jlmelanckier 

 Canadensis) , and it may possibly prove to be the fact that this 



