VINEYARD CONDITIONS IN LAKE ERIE VALLEY. 
57 
emerged. The host had been eonfined indoors during the winter, 
thus bringing out the hvmenopterous parasite on February 2. It is 
probable that the root-worm eggs were first parasitized by the dip- 
terous insect and that later the eggs along the margin of the cluster 
were parasitized a second time by LatJi- 
romeris jidix. The dipterous and the 
hvmenopterous insects are undoubtedly 
both primary parasites. 3 
VINEYARD CONDITIONS IN THE 
LAKE ERIE VALLEY. 
Before entering upon a discussion of 
methods of control undertaken against 
the grape root-worm during this inves- 
tigation it may be well to consider some of the changes which have 
occurred in vineyard conditions throughout the Lake Erie valley since 
the advent of this pest. 
In 1900, when the grape root-worm first appeared in injurious 
numbers in the Lake Erie valley, the grape industry was just emerging 
from a period of depression which had caused, for several years pre- 
vious, an almost complete cessation in planting of new vineyards. 
The period of low prices had resulted in indifferent care, amounting 
in some cases to positive neglect, thus creating a condition very 
favorable to the increase of this pest. Furthermore, the fact that 
practically all vineyards had been for several years in bearing and 
had a well established root system permitted the insect to become 
thoroughly disseminated through them before the unsuspecting 
owners were aware of its presence in numbers sufficient to affect the 
vigor of their vines. The tendency of most vineyardists at that 
time was to pull out declining vineyards rather than to go to 
the expense of fighting insect foes. Thus it happened that a com- 
bination of circumstances conspired to favor a general spread of the 
insect without creating widespread alarm. 
With the steady rise in the value of grapes since 1900, however, 
this condition has been reversed. Thousands of acres of new vine- 
yards have been planted, and the more progressive vineyardists are 
commencing to appreciate fully what an enormous amount of injury 
has been done to their old vineyards, and are greatly alarmed at the 
rapidity with which many young vineyards are falling a prey to this 
pest. 
The maximum crop yield for the Lake Erie grape belt occurred in 
1900, and amounted to S.000 carloads of fruit. At that time there 
Fig. 27.— Lathromeris fidUf, an egg-para- 
site of the grape root-worm: Antenna 
and fore wing. Very greatly enlarged . 
(Original.) 
a The authors are indebted to Mr. A. A. Girault, of the othYe of the state entomologist 
of Illinois, for the determination of the above-named parasites. 
