THE GRAPE CUECULIO. 6 



DISTRIBUTION. 



The grape curculio has been recorded from the New England 

 States (33) to Minnesota (25) and south to Missouri (7) and Florida 

 (33). Within this range there are records of its occurrence in the 

 following States: Arkansas, Florida, Illinois, Indiana, Kentucky, 

 Minnesota, Missouri, New York, North Carolina, Ohio, Pennsylvania, 

 Tennessee, and West Virginia. 



FOOD PLANTS. 



The adult curculios may be found upon the foliage and the larvse 

 within the fruit of probably all kinds of wild and cultivated grapes 

 that grow in the localities where the insect is found. There are no 

 records of either the adults or larvaB attacking under natural condi- 

 tions the leaves or fruit of plants other than the grape. During 

 the present investigation frequent search was made for the feed- 

 ing marks of the beetles on the foliage of various kinds of plants, 

 but they were not found elsewhere than on grape, nor were the 

 beetles or the larvse found about any other fruit. Brooks (30) 

 states that beetles in confinement, when deprived of other food, fed 

 on apple and cherry leaves and that one such female deposited an 

 egg in the fruit of Virginia creeper (Ampelopsis quinque folia) . This 

 egg hatched but the larva died at the end of two days. 



RECENT INJURIES. 



During the present investigation the following records were made 

 showing the destructiveness of the curculio at French Creek, W. Va. : 

 On August 14, 1916, several clusters of fruit were picked from an 

 unsprayed Concord grapevine. The clusters bore 163 berries and 

 of these 161 contained curculio stings. At least one-half of the 

 berries had already dropped from the clusters on account of being 

 infested with curculio larvaB. On August 18 of the same year the 

 entire crop of fruit from another unsprayed Concord grapevine was 

 gathered. The vine produced 2,382 fruits and of these 2,274, or 

 95.47 per cent, showed curculio injury and 108, or 4.53 per cent, 

 were sound. Probably half the grapes originally on the clusters had 

 dropped as a result of infestation, and were not counted. 



On August 23, 1917, about 50 grapevines of different varieties 

 growing about farmers' homes in the locality were examined. Counts 

 showed that from 40 to 95 per cent of all unprotected fruit had been 

 ruined by the curculio, the average loss being about 70 per cent. 



RESISTANCE OF CERTAIN GRAPES TO CURCULIO ATTACK. 



Opportunity was taken to note the extent of curculio injury to 

 about 25 different varieties of cultivated grapes and to three species 

 of wild grapes. The wild species were the fox grape (Vitis labrusca), 



