763 
No. 145.] 
else it too would be liable to be destroyed. This utterly exter¬ 
minates the aphis from the shrub, every insect being suffocated 
and dropping from the plant, so that 
“ unnumbered corses strew the fatal plain ” 
One measure more, and this the most important of all, whereby 
to subdue these insects, Remains to be stated A person who is 
acquainted with the aphides, and the several kinds of other in¬ 
sects which prey upon and destroy them in different ways, will 
never permit a valuable tree or plant to suffer injury from ihem. 
He will at once repair to the hedges and borders of the forests in 
his vicinity, and with a beating net, such as is used by entomolo¬ 
gists for gathering insects, or an opened inverted umbrella, or some 
other implement convenient for this purpose, he w'ill foon collect 
from the foliage a few scores of these natural enemies of the plant- 
lice, and conveying them alive in small boxes and vials, will set 
them free upon the tree or shrub ihat is infested. Most of the>e 
being in their larva state, and without wings, will not leave Iheir 
new situation so long as any food for them remains there. This 
is said to be the remedy to which all the more intelligent French 
and German gardeners are accustomed to resort in an emergency 
of this kind. The rapidity with w'hich these natural enemies of 
the aphides not only suppress but utterly exterminate them, in 
instances where they are so multiplied and excessively numerous 
as to seem unconquerable, is truly surprising. At one time the 
present season (1855) the cherry trees in my grounds became 
overrun with the Cherry plant-louse—to be considered hereafter— 
to such an extent that the under surface of the more young and 
tender leaves, and the succulent ends of the limbs and tw r igs, 
were all covered and black with them. If not checked it was 
evident that every tree would soon perish. I was about to im¬ 
port from the neighboring fields and forests a stock of the natural 
destroyers of these pests, when 1 found on examination that nature 
had already scattered numbers of these every where among the 
aphides. All apprehensions as to the result were hereupon at 
once allayed. A week afterwards, upon a careful inspection, 
not a single aphis could anywhere be found upon these trees. 
Of the teeming millions which were revelling theie so recently, a 
