GRAPE-BERRY MOTH IN NORTHERN OHIO. 
13 
The average length of the feeding period is seen to be 20.62 days, 
the maximum 37 days, and the minimum 14 days. The records 
extended throughout the regular hatching period, and therefore 
reflect vineyard conditions closely. 
LENGTH OF THE PREPUPAL PERIOD OF FIRST-BROOD INDIVIDUALS. 
In Table XVII are given the dates of cocooning and the length of 
the period from the time of spinning the cocoon until pupation for 
individuals some of which were supplied with sprayed foliage and 
others with unsprayed foliage. 
Table XVII. — Time of cocooning and length of prepupal period of 231 individuals of 
the first brood of the grape-berry moth, Sandusky, Ohio, 1917. 
Number of 
cocoons. 
Foliage unsprayed : 
Dates of cocooning — 
August 3 50 
August 4 50 
August 5 50 
August 7 39 
August 8 34 
Foliage sprayed : 
August 7 40 
August 8 24 
Dates of pupation. 
Number of pupae by days. 
Aug. 4 
17 
26 
3 
1 
5 
7 
28 
7 
:::::::::::: 
6 
21 
18 
1 
1 
7 
8 
21 
14 
1 
..... 
18 
11 
2 
11 
7 
3 
9 
10 
2 
11 
5 
12 
6 
13 
1 

Total number of pupae 
46 
4 
42 
8 
40 
10 
36 
3 
30 23 
4 
14 
10 
i 
Table XVIII. — Summary of Table XVII. Length of prepupal period of 231 indi- 
viduals of the first brood of the grape-berry moth, Sandusky, Ohio, 1917. 
Number individuals. 
Prepupal 
period. 
Cocooned on unsprayed 
foliage. 
Cocooned 
on sprayed 
foliage. 
67 
104 
23 
2 
13 
12 
6 
4 
Bays. 
1 
2 
3 
4 
5 
194 
37 
Average 1.77 
Maximum 3 
Minimum 1 
2.9 
5 
1 
