VINEYARD CONDITIONS IN LAKE ERIE VALLEY. 57 



emerged. The host had been confined indoors during the winter, 

 thus bringing out the hymenopterous 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 Lath- 

 romeris fidix. The dipterous and the 

 hymenopterous insects are undoubtedly 

 both primary parasites.^ 



VINEYARD CONDITIONS IN THE 

 LAKE ERIE VALLEY. 



Fig. 27.— Lathromeris fldix, an egg-para- 

 Bef ore entering upon a discussion of site of the grape root-worm: Antenna 



methods of control undertaken against ^^.'^J,^^' ^ery greatly enlarged. 

 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 8,000 carloads of fruit. At that time there 



a The authors are indebted to Mr. A. A. Girault, of the office of the state entomologist 

 of Illinois, for the determination of the above-named parasites. 



