STATE AGRICULTURAL SOCIETY. 
839 
APHIS. ITS PARASITES AND THEIR HABITS. 
harvest time had become gathered in the grain fields in such 
swarms as appeared sufficient to overwhelm and totally suppress 
it. Seeing them in such multitudes impressed me with the opin¬ 
ion that this insect would be'so reduced that perhaps it would 
not be noticed in the grain fields another year. Though since 
the fall sowed wheat and rye has come up, now in autumn, I find 
this aphis is quite as common upon the young grain as it was last 
spring, whilst scarcely any of these destroyers have yet found 
their way to it in these new situations. Hence it is to be feared 
it may become multiplied to be as numerous next year again as 
it has been the present year. 
Among the most efficient and interesting of these destroyers 
of the aphis are its parasitic foes. We see on many of the 
infested wheat heads from one to a half dozen or more of these 
lice which are very large, plump and swollen, of the color of 
brown paper, standing in a posture so perfectly natural you sup¬ 
pose they are alive. Touch them with the point of a pin, you 
find they are dead. Pick off a part of their brittle skin; you 
see there is inside a white maggot doubled together like a ball. 
Put one or two of these wheat heads in a vial, closing its mouth 
with a wad of cotton. In a week’s time or less you find running 
actively about in the vial some little black flies like small ants. 
These you see have come out from the dead lice through a circu¬ 
lar opening which has been cut in their backs. Drive one or two 
of these flies into another vial, and introduce to them a wheat 
head having some fresh lice. You will soon see the fly running 
about among them, examining them with its antennas. Having 
found one adapted to its wants, it dextrously curves its body for¬ 
ward under its breast, bringing the tip before its face, as if to 
take accurate aim with its sting. The aphis gives a shrug, 
indicating to us that the fly has pricked it with its sting and 
that by this operation an egg has been lodged under its skin, 
from which will grow a maggot like that first seen inside of 
the dead, swollen aphis. And thus the little fly runs busily 
around among the lice on the wheat heads, stinging one after 
another, till it exhausts its stock of eggs, a hundred probably 
or more, thus insuring the death of that number of these 
lice. And of its progeny, fifty we may suppose will be females, 
ky which five thousand moro will be destroyed. Wo thus 
see what efl’ecient agents these parasites are in subduing the 
insects on which they prey. 
