CONTROL OF THE GRAPE-BEERY MOTH. 9 
BAGGING GRAPE CLUSTERS. 
The bagging of grapes immediately after the setting of fruit, to 
prevent infestation by the berry moth, was tried in the season of 1914 
in the vineyard of the late*Mr. J. L. Spofford. Clusters on 25 vines 
were covered with paper bags, 2 and 3 pound sizes. The bags were 
fastened on the clusters with long pins and a slit was cut in the 
bottom of each bag to drain out whatever water might collect. 
The experiment was successful in so far as exclusion of the moth 
was concerned. Only 20 wormy berries were found in 100 clusters 
which averaged 32 berries to the cluster. This was a total infestation 
of only 0.62 per cent. However, the test was not severe, for the 
infestation of the grapes on the surrounding vines was light, being 
only 13.2 per cent. The infestation of the bagged clusters was due 
no doubt to oviposition which had taken place before the bags had 
been placed on the clusters. 
The cost of bagging, however, is prohibitive in commercial vine- 
yards in the Erie-Chautauqua grape region. Brooks (10) records, 
in control measures against the grape curculio, that one laborer in 
his employ could bag 1,200 clusters a day. This was probably 
exceptionally fast work. Using this as a basis and figuring 550 
vines per acre, each bearing 40 clusters, or a total of 22,000 clusters, 
the minimum cost of bagging an acre of grapes, according to 1914 
prices, would be as follows: 
Applying bags $22. 91 
Cost of bags, $1.15 per 1,000 25. 30 
Pins, $0.10 per 1,000 2. 20 
Total 50. 41 
This method of control, if followed at all, would be practicable only 
in a garden vineyard. 
HAND PICKING INFESTED BERRIES. 
Attempts to control the grape-berry moth by hand picking the 
fruit infested by first-generation larvae, in order to prevent subsequent 
infestation, were made in the seasons of 1914 and 1915. Clear-cut 
comparisons between the hand-picked plats and the checks were 
impossible because of the flight of moths from one row to another. 
Experiment in Adams and Gill Vineyard op North East, Pa., 1914. 
The plat chosen for the hand-picking experiment was a narrow strip 
of eight rows, containing slightly more than 1 acre, located in a 
corner of the vineyard, and bordered by a hedgerow. This plat was 
from three to four times as grossly infested as was the greater part of 
the vineyard. After the six rows nearest the hedge, the percentage of 
infestation declined quite rapidly as compared with that of the rest 
of the vineyard, and the south end, which was lower than the rest of the 
plat, was even more heavily infested than the rows next to the hedge. 
87069°— Bull. 550—17 2 
