222 
Journal of Agricultural Research 
Vol. I, No. $ 
number of cases some time elapsed after the larva had finished feeding 
before it began its cocoon, and in a few instances in which the insect was 
reared to maturity no cocoon was made. But such cases as that last 
mentioned resulted in diminutive adults. In most cases in which the 
cocoon making was delayed the supply of food had been small. 
The feeding period—determined, as indicated above, from the hatching 
of the egg to the beginning of the cocoon—varied, in a total of 579 cases 
observed, from 3^ to 1 8% days, with an average of about 7X days. 
In Table II all of the larvae carried through to the spinning of the cocoon 
are recorded, the months in which they spun their cocoons and their 
feeding periods being indicated. The weighted average feeding periods 
for each month and for the entire period are also shown. This is un¬ 
doubtedly higher in each case than the normal average, because, while 
the conditions of nature were imitated so far as possible in the cages, 
abnormal influences affected some of the larvae so that not only was their 
feeding period protracted, but some time passed after they had finished 
feeding before they started their cocoons. However, it is impossible to 
tell at what point to begin eliminating such larvae from the averages, 
so all are included. 
Table II .—Actual and weighted average feeding periods of larvce of Calliephialtes sp.for 
the period from May to October and the averagefor the season at Vienna Va., IQ12. 
Feeding period. 
Number of larvae in 
May. 
June. 
July. 
Aug. 
Sept. 
J Oct. 
Total. 
3*5 days. 
4 days. 
*2 
! 
2 
5 
21 
28 
O 
14 
r 9 
45 
20 
7 
4*5 da y s . 
c days. 
I 
8 
7 
37 
12 
89 
71 
72 
58 
49 
2% 
c.c days. 
7 
28 
32 
16 
6 days. 
6. c days. 
21 
7 
18 
26 
13 
14 
2 
I 
7 davs. 
14 
7 
16 
2 
2 
I 
7.5 days. 
8 days . 
14 
12 
8 
2 
2 
3 
x 
7 
i 
0 
34 
15 
10 
11 
18 
10 
21 
A 
8. < days. 
5 
8 
. 1 
o days. 
2 ! 
2 
3 
1 
3 
5 
10 
9 
*7 
A 
0. < days. 
1 
A 
10 days.. 
5 
¥ 
1 
2 
10. 5 days. 
I 
11 days. 
11.5 days. 
1 
I 
"" 2 "1 
12 days. 
1 
1 j 
4 
9 
I 
4 
II 
12. c days. 
I 
13 days. 
I 
.1 
A 
5 
12.C days. 
I ! 
*T 
2 
14 days. 
! 
5 
2 
0 
5 
3 
A 
14.5 days. 
15 days. 
I 
A 
15.5 days. 
4 
A 
4 
A 
16 days. 
4 
2 
4 
2 
16.5 days. 
J 
I 
18.5 days. 
I 
I 
Total. 
Q( 
143 
6 . 8 s 
157 
j 5*54 
1 —4.- 
79 
5 -*i | 
13 
8. 42 
92 
i 1 * 53 
579 
7- °7 
Average feeding 
period (days).. . 
yo 
6. 98 
