450 
ANNUAL REPORT OF NEW YORK 
HOP-APHIS. LONG KNOWN IN EUROPE. PI.IES DESCRIBED. 
ber of the previous year had been dry, an average or large crop had been 
grown. And when the quarter ending September had been wet and the 
December quarter very wet, a like result had followed.” This, however, was 
found to be modified by the temperature. “When the weather of the previous 
year has been such as to indicate a blight, there may be partial recovery, if 
Oie temperature succeeding should be hot,”—“with few exceptions, all the 
small crops were grown in years in which the temperature of the three summer 
months was below the average, and the large crops were produced in years in 
which the temperature of the like period was high.” 
Pqrhaps in no other group or family of insects are the different species so 
very closely akin to each other as in this of the Aphides. So nearly identical 
are most of them, both in their appearance and habits, that we know them to 
be distinct species only from the fact that they inhabit different plants, each 
one being unable to sustain itself upon any other than the plant to which it 
belongs. Being thus intimately related, we should confidently expect that the 
same atmospherical or other influence which causes one species to suddenly 
multiply and become extremely numerous, would operate upon and similarly 
affect the other species also. But this is by no means the case. As every one 
will remember, in the summer of 1861, all our fields of grain suddenly became 
so thronged with the Grain-aphis as to throw the whole country into alarm. 
Why did not the same cause which brought that insect upon us in such a re¬ 
markable manner, operate also to bring this insect upon the hops at that time, 
instead of two years later ? Or, if this hop insect was not then in our country, 
when it did appear in such vast numbers two years ago, why was not the same 
influence which occasioned its surprising multiplication then, felt also by the 
Grain-aphis, causing it to re-appear in our grain fields ? The two insects be¬ 
ing so intimately related, it is a mystery beyond the reach of human compre¬ 
hension, how some hidden influence comes to operate upon the one, causing it 
to multiply and increase so astonishingly, whilst the other remains passive and 
not in the least affected by it. 
This insect is not limited to the extensive hop plantations in the central 
parts of our State, but appears to have everywhere overrun the hop vines, both 
wild and cultivated. It was abundant the past summer in my own neighbor¬ 
hood, and specimens were also sent me from St. Lawrenco county, whereby we 
know that its range extends to the eastern and northern confines of the State, 
but farther than this we do not at present possess any definite information. 
This aphis appears to be identical with that which has long been known in 
Europe as the worst enemy to the hop, and which sixty-five years ago received 
its scientific name, Aphis Humuli or the Hop-aphis, from the German natu¬ 
ralist Schrank (Fauna Boica, vol. ii, p. 110.) 
The young lice, or “ nits,” are of a watery yellowish-white color with black 
eyes. As they arrive at maturity they acquire a green hue. They moult a 
few times, whilst attaining their growth, and their white cast skins are nume¬ 
rous, adhering to the hop leavos and intermixed with the honey dew. 
The flies or perfectly formed winged lice are green with tho back of the 
thorax and the breast black. The abdomen or hind body has black bands upon 
the back and along each side is one or two rows of black dots. Tho legs are 
