314 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
Table I. Summary of Length of Stages in the Life History 
Number of 
Stage 
Longest Shortest 
Average 
Individuals 
days 
days 
days 
Averaged 
Egg. 
6 
4 
4.8 
76 
First instar larva. 
6 
3 
4.1 
72 
Second “ “ . 
6 
2 
3.0 
70 
Third “ “ . 
5 
2 
3.3 
63 
Fourth “ “ . 
6 
2 
3.7 
52 
Fifth “ “ . 
6 
3 
4.4 
33 
Sixth “ “ . 
7 
3 
5.2 
15 
Prepupa. 
9 
1 
2.7 
13 
Pupa (Summer). 
13 
10 
11.4 
8 
Adult. 
23 
0 
13.5 
54 
Totals. 
87 days 
30 days 
56.1 days 
Table 
II. Summary of Instar Measurements 
Number of 
Stage 
Dimension 
Greatest 
Least Average 
Individuals 
mm. 
mm. 
mm. 
Averaged 
First instar larva. . . . 
length 
7 
3.7 
5.22 
45 
a i l n 
width of head 
0.4 
0.3 
0.39 
45 
Second instar larva.. . 
length 
11 
6. 
7.66 
45 
i i a a 
width of head 
0.6 
0.46 
0.58 
45 
Third instar larva . . . 
length 
17 
8 
12.2 
39 
i l i l i l 
width of head 
0.93 
0.66 
0.83 
39 
Fourth instar larva.. . 
length 
26 
11 
17.2 
36 
ii Li i i 
width of head 
1.53 
1.14 
1.31 
38 
Fifth instar larva . . . 
length 
34 
18 
26.3 
27 
a a a 
width of head 
2.0 
1.66 
1.89 
28 
Sixth instar larva 
length 
43 
23 
34 
20 
< i a a 
width of head 
2.87 
2.13 
2.5 
20 
deposited singly or in groups on any part of the plant, but especially 
on the leaves. 
As embryological development proceeds, the eggs become spotted 
with brown. These spots are irregular in shape, of different sizes and 
scattered irregularly, but their relative positions in different eggs are 
the same. The largest one is near the micropyle and is always present. 
% 
Between these spots are numerous, conspicuous, whitish, flaky spots 
beneath the chorion. The larvae hatch by eating nearly circular 
holes in the egg shells 0.25 mm. in. diameter. Upon emerging, the 
larvae generally devour a portion of the remaining empty egg shell. 
They may devour all but the attached portion of the chorion. 
Larvae. They are longitudinally striped (Fig. 11, 3, 4, and 7) or 
banded, and walk with a looping gate. All stages may be readily col- 
