12 
SUMMARY OF LIFE HISTORY. 
As a rule, there are eight molts after the egg stage, although occa- 
sional males molt only seven times. The entire period from the egg 
stage to the adult averaged 295.3 days for 19 individuals, 11 of which 
were males averaging 281 days with a variation of 233 to 321 days, 
and 7 females averaging 321 days, with a variation of 291 to 397 
days. About a year is required for the full development of a 
generation. 
The duration of the different instars is shown in the accompanying 
table: 
Duration of instars of changas reared from the egg. 
Ins tar. 
Number of 
indi- 
viduals 
averaged. 
Duration in days. 
Maximum. 
Minimum. 
Average. 
1 
52 
38 
31 
32 
27 
20 
17 
15 
67.5 
59.5 
65.0 
58.5 
49.0 
94.5 
62.0 
75.5 
23.0 
13.0 
12.5 
16.5 
18.0 
25.0 
27.0 
38.0 
40.2 
2 
29.4 
3 
26.8 
4 
27.5 
5 
30.0 
6 
47.5 
7 
45.7 
8 
54.1 
The preoviposition period of adult females is long. Three indi- 
viduals averaged 79 days between the time of becoming adult and 
the first egg laying, 62 days being the shortest time and 93 the 
longest for this period. 
That adults may live several months under favorable circum- 
stances was shown by tests made with adults placed in battery jars 
filled with earth and provided with ample vegetable food. The 
longest adult life recorded was of a male which was eaten by a 
female 160 days after the final molt. An adult female taken in 
the field died a natural death after being kept alive for 127 days. 
The numerical proportion of males to females bred in captivity 
was about equal, and the same is true of captures made in the field. 
Individuals have been brought to the adult stage every month of 
the year in the insectary, but there seems to be a fairly well-defined 
preponderance of final molts during the fall months. It is possible, 
therefore, that the flight to lights so marked during October, Novem- 
ber, and December is in part at least a nuptial flight. All stages may 
be found in the field at any time of the year. 
EGG STAGE. 
The newly egg is gray in color and oblong-oval in shape, with 
a shiny, unsculptured surface (PL III, fig. 1), measuring about 3 
millimeters long and 1.7 millimeters wide. The egg increases con- 
