34 ANNUAL REPORT OF NEW YORK 
and these fly away from the winter grain to plant their race upon the 
spring sowed wheat and oats. 
The latter part of June, when the grain has advanced so that the heads 
or cars begin to put forth, two most remarkable changes occur in this 
insect, whereby it appears to become another creature, a different species, 
in the middle of summer from that which is seen in the spring and autumn. 
One of these changes is in its habits. Before the heads appear it lives 
tingly,' scattered about upon the leaves and stalks of the grain, and the 
young lice, as fast as they are born, leave their parents and wander away. 
But no sooner are the heads protruded from their sheaths prepaiatoiy to 
blooming and growing the kernels of the grain, than this aphis wholly 
forsakes all the other parts of the plant and becomes congregated upon 
the heads, evidently because the juices which the plant elaborates for the 
growth of its flowers and seeds are much more nutritious, more dainty and 
palatable to these insects, than are the juices which circulate in the leaves 
and stalks. They here fix themselves upon the base of the chaffs which 
envelop the kernels, and inserting their beaks, they suck out the juices 
which should go, first, to grow the flowers, and after that to fill and perfect 
the kernels. And now the young lice which are born, instead of scattering 
themselves and traveling away, settle down closely around their parent, 
crowding as compactly together as they can stowithemselves. Thus it 
comes to pass that when these insects are numerous, as we have recently 
had them, in many of our grain fields, scarcely an ear can be found which 
has not a cluster of these lice around the base of almost every kernel, all 
with their tiny bills inserted therein, pumping out the juices which should 
go to swell and perfect the seed. Thus, this grain aphis from being a 
solitary insect, wandering about singly upon the leaves and stalks, becomes 
a gregarious insect, clustered together in flocks, and remaining fixed and 
stationary upon the lower or but ends of the kernels. 
At the same time another change, equally remarkable, takes place in the 
color of these insects. So long as they nourish themselves on the coarse 
juices of the stalks and leaves, their bodies are all of a grass-green color. 
But when they come to feed on the more delicate juices of the flowers, 
they begin to bear young of an orange color. One of the grass-green 
insects having stationed herself at the base of a kernel, the next day, in 
the group of little ones around her, a yellow one will occur, all the others 
being green like their parent. A day or two later, as the nourishment she 
derived from the leaves becomes more dissipated from her body and 
replaced by that now obtained from the kernels, half the young she pro¬ 
duces will be of this yellow collor. And still later all the young are 
yellow, no green ones being any longer born. And the older ones after a 
time dying and disappearing, all these insects some weeks before harvest 
time, become changed to a yellow color, their hue inclining more to red in 
some and to yellow in others. 
It is truly curious that this green insect, thus, on coming to feed on the 
juices which grow the flowers, begin to produce young of a gay yellow 
color similar to that of the flowers. 
By depriving the kernels of a portion of the milky juice which should go 
