THE GRAPE-BERRY MOTH. 51 



made by Prof. H. A. Gossard in Ohio during the same season. 

 Searches in badly infested vineyards every season since 1906 have 

 shown a similar condition. This habit of the larvae may be due to 

 the fact that at this season the leaves upon the vines are somewhat 

 withered and brittle. Hence it would appear to be more difficult 

 for the larvae to fold the flap of the portion of the leaf cut out for 

 making the cocoon, whereas 7 when the leaves have fallen to the 

 ground and have absorbed moisture from the soil they are less brittle 

 and the flap can be folded much more readily. Whether this is the 

 true cause of the larvae seeking the leaves on the ground upon which 

 to form their overwintering cocoons or not the fact that they do so 

 has an important bearing upon the practice of destroying fallen 

 leaves as a means oi destroying the overwintering pupae. Since 

 most of the cocoons are made upon a small number of leaves which 

 are stuck more or less firmly to the ground there is little likelihood 

 that many of them will be blown into piles in the corners of vine- 

 yards or into hedgerows as has been supposed. Unless these infested 

 leaves are gathered carefully before the period of soaking rains during 

 the late fall and winter they are likely to fall apart and leave the 

 cocoons containing the pupae in the vineyard. Perhaps an attempt 

 to gather these infested leaves from the ground beneath the trellis 

 during the middle or latter part of October, before the remainder of 

 the leaves have fallen from the vines, would prove more effective than 

 to try to destroy all of the leaves at a later date. There is no doubt 

 that large numbers of pupae can be collected in this way over limited 

 areas where the infestation is heavy. Unfortunately, however, the 

 vineyardist is too busily engaged hi harvesting his grape crop at this 

 time to adopt this method of control. 



PLOWING IN LATE FALL OR EARLY SPRING. 



Since it is evident that few of the infested leaves are likely to be re- 

 moved by the winds from the ground beneath the trellis it is quite possi- 

 ble that large numbers of them could be destroyed by plowing the badly 

 infested portion of the vineyards immediately after the crop of grapes 

 is harvested and before the rest of the leaves have fallen from the 

 vines. Plowing at this time would be more likely to insure the cover- 

 ing of the infested leaves than if all of the leaves had fallen, for then 

 the loose leaves would be likely to drive ahead of the plow and force 

 some of the infested leaves to the surface. 



Many vineyardists object to fall plowing of vineyards, and, where it 

 is impracticable, early spring plowing is suggested. Care should be 

 taken to throw the soil well under the trellis so that all of the leaves 

 may be covered. Since only a small percentage of the moths emerge 

 before June 1, plowing up to the trellis during the month of May 

 would doubtless cover many of the pupae. 



