CONTROL OF THE GRAPE-BERRY MOTH. 33 



tioned as being made when the berries were just touching. This was 

 probably due to the fact that the absence of the early application 

 permitted all of the first brood to enter the berries and heavier ovi- 

 position later resulted. Furthermore, dependence upon an applica- 

 tion as late as August 12, alone, is open to objection even if the second- 

 brood control was very good, because infestation by the first brood 

 will usually seriously thin out the clusters, and too, the spray remains 

 longer on the berries, leaving them seriously stained at harvest time. 

 This application is harder to make than is the earlier one because the 

 foliage at the later date is much heavier. The value of the applica- 

 tion is largely that of an emergency measure, at a time when the first 

 brood has not been controlled. 



A three-spray schedule was tried in Plat IV of the Bartlett (lower) 

 vineyard. The infestation was less than in Plats III and V, which 

 had been sprayed twice. However, in this instance the difference was 

 not of commercial importance and would not pay for the extra appli- 

 cation, and the fruit was stained so badly by the last application as 

 to reduce materially its value on the basket market. This third 

 application could be of value in this region only under extraordinary 

 conditions, when faulty work or lack of spray materials and labor or 

 unfavorable weather had prevented the control of the first brood. 



A comparison of the results of different spray schedules is given in 

 Table 23. The average infestation of plats where two applications 

 were made was distinctly heavier than was the infestation in the one 

 plat where three applications were made. It should be noted, how- 

 ever, that where the plats sprayed two and three times were adjacent 

 in the same vineyard, the difference in infestation was very slight. 



It also shows that the single application may produce fair control 

 if the infestation is light, but that on the whole dependence on a 

 single application is unsatisfactory. 



A spray application before the grapes blossomed, followed by the 

 usual two applications after the falling of the blossoms, was tried in 

 one plat in each vineyard in 1914. No beneficial results of this spray 

 could be noted when the final counts were made. The importance of 

 this spray was brought into question soon after its application, for 

 very few larvae were found in the clusters before the next was applied. 

 Even had they been numerous at that time, the "preblossom spray" 

 could hardly have been effective, as practically all of the poison that 

 did adhere to the clusters when applied fell off a few days later with 

 the flower caps. 



This early spray was applied again in 1915 in all three vineyards, 

 but since practically no larvae were found until the blossoms fell, these 

 plats were discarded. 



