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



The rearing records show clearly the value of winter exposure in a 

 vineyard in reducing the number of moths that will be present the 

 following season. 



A comparison of Lot III with Lot I shows how plowing, if inju- 

 diciously practiced, may increase vineyard infestation. If a furrow 

 is thrown up to the vines in late fall, after the larvae have spun their 

 cocoons under the vines, it will give the hibernating pupae winter 

 protection. And if the earth is plowed away before the time of 

 moth emergence, these artificially protected insects are released. 



It is obvious that the protection of hibernating j^upae should be 

 avoided whenever practicable. Plowing to the vines in late fall 

 after harvest should be avoided as far as possible. Hedge rows and 

 brush along vineyards should be removed. This last coincides with 

 good vineyard practice and is of value also in reducing danger of leaf- 

 hopper injury. 



Unnecessary Shade. 



Shade in a vineyard favors the berry moth. Where the growth is 

 vigorous and the foliage dense, or where vines have been trained so 

 as to give an unusual amount of shade, the infestation invariably is 

 heavier than in adjacent parts of the vineyard or in vines giving less 

 shade. Vigorous growth is desired, of course, but when horticultural 

 considerations do not prevent, vine training systems which give 

 unusual shade should be avoided. 



DESTRUCTION OF LEAVES IN FALL. 



Destruction of the hibernating generation in the cocoon, the first 

 control measure to be recommended, was tried in the fall of 1914. 

 zn. a small block in the McDonald vineyard the writer attempted 

 removing cocoons by raking out the leaves under the trellis. Upon 

 examination of the leaves thus collected it was found that practically 

 all of the cocoons had fallen out. In the following season when 

 counts of berries infested by first-brood larvae were made no difference 

 between this block and the check was noted. 



During the seasons of 1914, 1915, and 1916 the writer and his 

 associates collected approximately 30,000 cocoons for rearing. No 

 system could be devised to aid in collecting these cocoons and the 

 work was necessarily done by hand. It was always a slow and 

 tedious process and is impracticable as a means of control, since the 

 cocoons are usually spun, except in very dry seasons, in leaves that 

 are sodden and ready to fall apart, and not in fresh, crisp leaves. 

 Frequently the cocoons are spun in the leafage of chickweed and 

 sorrel and in other leaves which ordinarily would escape collection. 



