CONTROL OF THE GRAPE-BERRY MOTH. 
19 
Table 9. — Percentage of infestation in experimental plats, Miller and Carlburg vineyard, 
North East, Pa., 1915. 
First brood. 
Second brood. 
Plat No. 
Num- 
ber of 
vines. 
Num- 
ber of 
clus- 
ters. 
Total 
berries. 
Infest- 
ed ber- 
ries. 
Infesta- 
tion. 
Num- 
ber of 
vines. 
Num- 
ber of 
clus- 
ters. 
Total 
berries. 
Infest- 
ed ber- 
ries. 
Infesta- 
tion. 
I 
25 
25 
25 
25 
25 
25 
25 
25 
25 
25 
25 
25 
601 
544 
492 
460 
575 
796 
712 
661 
561 
716 
695 
792 
14,028 
12,550 
11,235 
13, 692 
13, 705 
19,544 
22, 736 
18, 508 
16, 269 
21, 480 
20, 850 
23,882 
450 
414 
519 
343 
289 
479 
1,264 
795 
901 
1,024 
1,013 
3,533 
Per ct. 
3.21 
3.29 
4.53 
2.51 
2.11 
2.45 
5.99 
4.18 
5.53 
4.53 
4.86 
14.87 
20 
20 
20 
20 
20 
20 
20 
20 
20 
20 
20 
20 
10 
4S1 
435 
397 
368 
460 
637 
570 
529 
459 
513 
556 
634 
340 
10,822 
9,640 
9, OSS 
10.956 
10,960 
15, 625 
16, 587 
14,783 
13,005 
15,441 
14,430 
19', 135 
9,380 
S47 
951 
2,887 
432 
967 
1,188 
5,523 
2,793 
2,738 
3,152 
3, 95S 
11,803 
4,710 
Per ct. 
7.91 
II 
9.86 
Ill 
31.77 
IV 
3.94 
V 
9.56 
VI 
7.60 
VII 
33.31 
VIII 
18.89 
IX... 
21.05 
X 
20.41 
Check A 
28.80 
Check B 
61.67 
Check C 
50.21 
In spite of the exceedingly adverse weather conditions at the time 
of spraying, all plats but one on which arsenate of lead with soap had 
been applied twice with "trailers" (Plats I, II, IV, V, and VI) showed 
a satisfactory reduction of the grape-berry moth from a commercial 
standpoint. In one plat where rain followed immediately after the 
second spray application (Plat III) the results must be disregarded. 
The rain also probably reduced the efficiency of control hi Plat II, 
which was sprayed just before Plat III, and to a less degree may have 
affected others; but the results showed that when the spray had 
time to dry on the grape berries before ram, a fairly satisfactory con- 
trol could be secured. Failure to control resulted hi plats where 
spray was applied with "set nozzles" instead of "trailers 7 ' (Plat X), 
where the soap was omitted from the spray mixture (Plat IX), and 
where flour paste was used as adhesive instead of soap (Plat VIII). 
Bordeaux mixture and soap were used without arsenate of lead (Plat 
VII) and no effect, repellent or insecticidal, was noted. Nicotine 
sulphate appeared to add nothing to the effectiveness of the solution 
(Plats V and VI). Laundry soap (Plats I, IV, and VI) and fish-oil 
soap (Plats II and V) were both used apparently without distinct 
advantage for either. The plat sprayed with 5 pounds of arsenate 
of lead (paste) to 50 gallons of liquid (Plat II) was much more heavily 
infested than the plat sprayed with only 3 pounds of arsenate of 
lead (paste) to 50 gallons (Plat IV), but as the second application of 
spray on Plat II was closely followed by rain the infestation in this 
plat was probably also somewhat heavier naturally. (Compare check 
plats B and C with A.) 
