2 BULLETIN 550, U. S. DEPARTMENT OF AGRICULTURE. 



The results of these experiments constitute the chief subject matter 

 of this bulletin. Only such biological data as are necessary as a 

 basis for the remedial work are included. Various control measures 

 which have been employed are given place in the earlier part of the 

 paper, but chief attention is devoted to spraying, which has proved 

 to be the most effective means of control. 



FOOD PLANT. 



The grape, as far as is known, is the only food plant of the larva 



of the grape-berry moth, and since the larvae usually feed upon the 



grape berry, it is from this habit that its common name is derived. 



Before the berries are developed, the few early larvae feed in the 



blossom clusters. In confinement larvae may feed sparingly on grape 



leaves and stems. 



DISTRIBUTION. 



The distribution of the grape-berry moth extends throughout the 

 United States from east of the Great Plains to the Atlantic, and 

 from the southern portion of the Canadian Province of Ontario to 

 the Gulf of Mexico. The States from which it has been recorded in 

 publications and in unpublished files of the Bureau of Entomology 

 are as follows: Massachusetts, Connecticut, New York, New Jersey, 

 Pennsylvania, Delaware, Maryland, Ohio, Indiana, Illinois, Wiscon- 

 sin, Michigan, Missouri,' Iowa, Nebraska, Kansas, Virginia, South 

 Carolina, Florida, Alabama, Kentucky, Louisiana, Arkansas, and 

 Texas. Most frequent complaints of its destructiveness have come 

 to the Bureau of Entomology from New York, Pennsylvania, New 

 Jersey, and Ohio. 



ECONOMIC STATUS. 



The grape-berry moth is a major grape pest in the eastern United 

 States, on the whole probably being exceeded in destructiveness by 

 the grape rootworm (Fidia viticida Walsh) and the grape leaf- 

 hopper (TypTilocyba comes Say). However, its exact status as a 

 pest is uncertain. In some grape-growing regions, within the limits 

 of distribution, its presence is ignored or even unknown to the 

 growers. It is exceedingly erratic and local in occurrence, and the 

 damage which it inflicts varies greatly from year to year. The his- 

 tory of the grape-berry moth in the Erie-Chautauqua grape belt is 

 an example of this variation. In the western part of the grape belt, 

 in Pennsylvania, during the season of 1916 this insect was by far the 

 most destructive grape pest; in the eastern part of the grape belt, in 

 New York, it was not generally regarded seriously, yet Slingerland 

 in 1904 reported it as very destructive throughout all of this region, 

 particularly near Brocton, N. Y., where in one vineyard as high as 

 90 per cent of the fruit was ruined. 



