.£ 03/j ? 
Packard.] THE POPULATION OP AN APPLE THEE. 161 
7, The l^apulatitro af am Jtpple Tree. 
A FRENCH author has written a very pleasant little 
book entitled the “Population of a Pear Tree.” Of 
the population of an apple tree a ponderous tome 
could be written, but in this essay on the insects injuring 
this facile princeps of our fruit trees, we shall confine our¬ 
selves mainly to the more injurious kinds, giving a brief and 
condensed account of the most important species. About 
seventy-five species ii^ all are known to prey upon the apple 
tree. We may first consider those kinds found 
PREYING UPON THE ROOTS. 
The Pear Blight, or Eriosoma pyri (Fig. 127; a, the gall; 
b, larva; c, female ; d , leg ; e, beak ; /, antenna of female; 
Fig. 127. 
Blight Insect. 
g, of larva; after Riley) sometimes causes a good deal of 
disturbance to the health of the tree, lessening the> vigor 
of its growth and causing the leaves to turn of a paler and 
more yellowish hue than usual. If there is no borer under 
