10 
BULLETIN 901, U. S. DEPARTMENT OF AGRICULTURE. 
Table IV. — Time and duration of larval feeding period of A. chalybea, North East, Pa., 
1917. 
jjate 01 
Date of 
entering 
ground. 
Aumuer 
-Uuration 
Dcite of 
Date of 
entering 
ground. 
-iN umDer 
jJuraLion 
hatching. 
of ]a^^ fe. 
of period. 
lid H->llllig . 
ui lal V ctr. 
of period. 
Days. 
Days. 
June 4 
June 28 
2 
24 
June 17 
July 8 
3 
21 
12 
July 1 
1 
19 
17 
10 
1 
23 
13 
4 
2 
21 
17 
11 
1 
24 
13 
5 
1 
22 
19 
10 
3 
21 
13 
8 
4 
25 
19 
11 
4 
22 
14 
7 
1 
23 
19 
13 
3 
24 
14 
8 
2 
24 
19 
li 
1 
25 
14 
9 
2 
25 
19 
20 
1 
31 
14 
17 
1 
33 
20 
15 
2 
25 
15 
11 
2 
26 
20 
17 
4 
27 
15 
13 
2 
28 
20 
20 
1 
30 
16 
8 
1 
22 
16 
10 
1 
2 24. 26 
1 Total. 
2 Weighted average. 
DURATION OF SECOND LARVAL STAGE. 
The duration of the second stage, of 60 larvae reared, varied from 
5 to 11 days with an average of 6.95 days, as shown in Table VI. 
rn ^7 7^- ^ 7 7 . / The total period covered bv records on 
Table V . — Fir.H larval stage^ oj 
larvae of this stage extended from June 9 
to Julv 8. 
A. chalybea, North East, Pa. 
1917. 
Number 
Duration 
of larvae. 
of stage. 
Days. 
1 
4 
2 
5 
1 
6 
8 
7 
26 
9 
8 
9 
8 
10 
10 
11 
1 
12 
1 
13 
1 
14 
168 
2 8. 74 
1 Total. 
Weighted average. 
DURATION OF FEEDING PERIOD OF THIRD LARVAL 
STAGE. 
The duration of the feeding period of 
the third stage, of 47 larvse reared, varied 
from 5 to 13 days with an average of 
8.53 days, as is shown in Table VII. The 
total period covered by records on larvae 
of this stage extended from June 15 to 
July 20. 
DURATION OF PERIOD IN GROUND. 
The duration of the period in the ground 
varied from 15 to 25 days with an average of 19.24 days. The total 
period covered by records on the immature stages in the ground and 
emergence are given in full in Table VIII. 
DURATION OF PREPUPAL PERIOD. 
The duration of the prepupal period, of 23 individuals recorded, 
varied from 7 to 13 days with an average of 9.17 days, as shown in 
Table IX. The period covered by records on prepupae extended 
from June 28, when the first larvae entered the ground, to July 24, 
when the latest transformed to pupae. 
DURATION OF PUPAL PERIOD. 
The duration of the pupal period of 17 individuals recorded 
varied from 7 to 10 days with an average of 8.47 days, as sho'%vn in 
Table X. Records on this stage extended from July 17 to 31. 
