8 BULLETIN 19, U. S. DEPARTMENT OF AGRICULTURE. 
During the period from 1897 to 1904 the writer of this paper resided 
at Westfiekl. N. Y.. during the summer months and had the opportu- 
nity to observe the development of the outbreak of 1900 to 1904. 
There was not a sudden appearance of this pest in a single season, but 
a steady increase in numbers for several consecutive seasons preced- 
ing the so-called outbreak of 1900. On the other hand, during the 
summer of 1903 there was an apparent sudden disappearance of the 
insect from many vineyards which during the two previous seasons had 
been badly infested and suffered serious injury to the foliage during the 
seasons of 1901 and 1902. In fact, after the season of 1904 this pest 
disappeared from the vineyards of this area of serious infestation to 
such an extent that treatment was deemed unnecessary. For several 
years after this disappearance in destructive numbers of the insect 
from the vineyards in the vicinity of Westneld. X. Y.. its occurrence 
in vineyards throughout the Lake Erie Valley was not considered of 
sufficient importance to warrant treatment. In 1909. however, during 
the conduct of vineyard experiments at North East, Pa., the appear- 
ance of this pest in injurious numbers was again observed in portions 
of several widely separated vineyards throughout the township. In 
the latter part of the season of 1910 the area of serious injury was 
much more widespread and its increase was viewed with alarm by 
vineyardists. and in the season of 1911 a number of the more pro- 
gressive growers equipped themselves to fight the pest. During 1911 
the injury wrought by the pest was greater than in preceding years, 
and the infestation was more widespread. The summer was unusually 
hot. and this resulted hi the development of an almost full second 
brood which worked great injury to the vines late in the season. 
Immense numbers of adults went into hibernation, and large numbers 
of them emerged and made then appearance in the vineyards in the 
spring of 1912. Early in the season of 1912. on account of the pres- 
ence of so many overwintering adults, there was every indication that 
the injury by this pest would be very great. There was an appar- 
ently normal development of the first brood of nymphs, and by the 
middle of the summer the injury in many vineyards was quite severe. 
Fortunately, however, the months of July and August were unseason- 
ably cool. The low temperatures which prevailed during these two 
months so greatly retarded the development of the nymphs of the first 
brood that only a small percentage of the adults transforming from 
them deposited eggs for a second brood of nymphs. Hence there was 
not such a great increase in numbers of the insect during the latter 
end of the season of 1912 as there was at the end of the hot season of 
1911. Nevertheless the injury done by this pest to many vineyards 
was very great. The injury to the foliage, coupled with the coolness 
of the summer, resulted in badly infested vineyards, in a retardation 
of the cane growth, in a lack of proper development of the size of the 
