GRAPEVINE FLEA-BEETLES. 
17 
TIME AND DURATION OF THE LARVAL FEEDING PERIOD. 
The duration of the feeding period of 190 larvae varied from 15 to 
23 days with an average of 18.59 days. The period covered by 
records on feeding larvae extended from June 26 to July 26. Complete 
data on time and duration of this period are given in Table XIX. 
Table XIX. — Time and duration of larval feeding period of A.woodsi, North East, Pa.^ 
1917. 
Date of 
entering 
ground. 
Number 
Duration 
Date of 
Date of 
entering 
ground. 
Number 
Duration 
hatching. 
of larvae. 
of period. 
hatching. 
of larvae. 
of period. 
Days. 
Days. 
June 26 
July 14 
5 
18 
July 4 
July 25 
2 
21 
26 
15 
6 
19 
5 
22 
26 
17 
26 
16 
1 
20 
5 
23 
7 
18 
26 
17 
11 
21 
5 
24 
2 
19 
July 2 
20 
6 
18 
5 
25 
4 
20 
2 
21 
7 
19 
6 
23 
3 
17 
3 
21 
9 
18 
6 
25 
7 
19 . 
3 
22 
15 
19 
7 
23 
6 
16 
3 
23 
9 
20 
7 
24 
3 
17 
3 
24 
3 
21 
7 
25 
1 
18 
3 
2.5 
22 
9 
24 
2 
15 
3 
26 
1 
23 
9 
25 
4 
17 
4 
22 
9 
18 
9 
26 
1 
18 
4 
23 
34 
19 
4 
24 
5 
20 
1190 
2 18.59 
» Total. 2 Weighted average. 
DURATION OF THE FIRST LARVAL STAGE. 
The duration of the first Jarval stage was from 4 to 11 days with an 
average of 6.35 days, as shown in Table XX. The period covered 
by records on larvae of this stage extended 
from June 26, the earliest recorded date of 
hatching, to July 15, the latest recorded date 
of passing the first molt. 
Table 'KX.— First 
stage of A. ivoodsi, 
East, Pa., 1916. 
larval 
North 
Number 
Duration 
of larvae. 
of stage. 
Days. 
2 
4 
29 
5 
85 
6 
74 
7 
39. 
8 
4 
9 
3 
10 
1 
11 
1237 
2 6.35 
DURATION OF SECOND LARVAL STAGE. 
The duration of the second stage of 209 
larvae was from 4 to 9 days with an average 
of 6 days, as shown in Table XXI. The total 
period covered by records on larvae of this 
stage extended from July 1 to July 21. 
DURATION OF FEEDING PERIOD OF THIRD LARVAL STAGE. 
Total. 
Weighted average. 
The duration of the feeding period of the 
third larval stage of 189 larvae varied from 4 
to 9 days with an average of 6.62 days, as shown in Table XXII. 
The total period covered by records of larvae in this stage is from 
July 6 to July 26. 
I 
