THE GRAPE-BERRY MOTH. 65 



of the vineyard where the infestation has been heavy during previous 

 seasons. The time of this second application is approximately from 

 June 20 to 30. 



The third application should be made when the berries are about 

 the size of buckshot (see PI. VIII, fig. 1). If the foliage is dense, the 

 " trailer" method of application should be employed, and if the grape 

 leafhopper is at all numerous the tobacco extract should be added to 

 control the latter insect. The time of this third application is 

 approximately from July 5 to 15. 



The poison-spray treatments recommended against the grape root- 

 worm are also covered by the second and third applications against the 

 grape-berry moth. 



It should be distinctly understood by .the vineyardist that the 

 arsenate of lead is the active killing agent employed against the 

 larvae of the grape-berry moth and that it is applied with the Bor- 

 deaux mixture, which is a fungicide, in order to avoid the duplication 

 of applications. 



Where a considerable number of infested grape berries are observed 

 on vineyard areas that received a poison-spray application before 

 the grape blossoms opened, and a heavy double application after the 

 berries had formed, it may be necessary to hand pick the inf ested 

 berries during the latter part of July before many of the larvae of the 

 first brood have fully developed. By removing these larvae from the 

 vineyard and destroying them by immersing the infested berries in 

 boiling water, the amount of infestation by ' the second brood of 

 larvae may be greatly reduced. 



Should only limited areas of the vineyard prove to be seriously 

 infested at the approach of the picking season, as frequently occurs, 

 it is suggested that the vineyardist remove the fruit from these 

 vines as early as possible, for in doing so he may be able to remove 

 a good many of the larvae from the vineyard which would otherwise 

 remain there to reinfest the crop of the succeeding season. 



In addition to the control methods suggested against the larvae, 

 special effort should be made to destroy the pupae which pass the 

 winter in the fallen leaves, on the ground beneath the trellis. (See 

 fig. 22.) As previously mentioned, observations made during this 

 investigation indicate that the majority of the pupae over- winter in 

 cocoons made upon leaves which have fallen prematurely to the 

 ground beneath the trellis. These leaves are frequently stuck to the 

 soil and are in a state of semidecay before the rest of the foliage has 

 fallen from the vines. Hence there is little likelihood that many of 

 these leaves bearing the cocoons will be blown out of the vineyard. 

 For this reason it is quite probable that if 2 or 3 inches of soil are 

 thrown under the trellis in late fall or early spring many of the pupae 

 may be destroyed by this operation. It is not known positively that 



