10 THE HOP APHIS IN THE PACIFIC REGION. 
In 1911 the hops at Santa Rosa, Cal., were severely attacked by 
this aphis. In fact, if the hop crop of the world had not been small 
and the demand for hops consequently very great, many of the 
growers in this section would have been unable to dispose of their 
crops. During the same season the financial loss due to injury by 
this aphis to the crops on two large yards in British Columbia was 
estimated at $80,000. 
In 1912 the loss due to this insect was particularly severe in Ore- 
gon. One company which handles about 20,000 bales estimated 
that 50 per cent of their hops were badly -damaged and would sell 
for 15 cents per pound, while 30 per cent was slightly damaged and 
would sell between 15 and 18 cents per pound. The remaining 20 
per cent was not injured and would sell for the prevailing price of 
20 cents. At this rate the loss would aggregate $124,000. The crop 
on a yard of 110 acres was so severely injured that 20 acres were not 
worth picking. The loss in this yard was $12,000. 
The damage in these cases was unusually severe, but this pest if 
not controlled is, under favorable conditions, capable of causing 
such injury to both the hop vines and the hop cones as to entail a 
total loss. 
LIFE HISTORY. 
HIBERNATION. 
The winter egg is deposited by the oviparous female upon the 
plum, prune, and hop in the Pacific Coast States and upon the sloe, 
plum, bullace, 1 and probably the hop in England and- Continental 
Europe. 
The first generation and the winged migrants were observed upon 
French prune at Santa Rosa and Perkins, Cal., during May and 
June in 1911 and 1912. The migrants which were observed May 29, 
1912, were upon the ordinary though tender foliage, but those 
observed later in the season were found only upon some very succu- 
lent, sucker like growths. No hop aphides were found upon the 
surrounding older and tougher leaves. This observation was made 
both in Santa Rosa and Perkins, and it was found that by selecting 
such growths aphides could almost invariably be found. 
APHIDES ON HOP ROOTS. 
Prof. W. T. Clarke, of the California Experiment Station, stated 
that while studying this insect at Watson ville, Cal., during the last 
of January or first of February, 1904, some hop roots were brought 
to him on which were many living hop aphides. He stated that 
there is no doubt about the identification of this insect. The writer 
Journ. Board Agr. Great Britain, vol. 19, No. 4, p. 297, 1912, 
