228 
Journal of Agricultural Research 
Vol. X, No. 3 
Table) VI .—Relative length of pupal stage of males of Calliephialtes sp. from fertilized 
eggs and those from partheno genetic eggs at Vienna , Va., IQI2. 
Number of pupae from — 
Pupal period. 
Fertilized 
Parthenoge- 
eggs. 
netic eggs. 
7.5; days. 
1 
8 days. 
I 
8.5 days. 
3 
3 
9 days. 
8 
6 
9-5 days. 
9 
6 
10 days. 
7 
2X 
10.5 days. 
/ 
5 
12 
11 days . 
I 
Total. 
34 
49 
Average pupal period, days. 
9. 44 
9.87 
The truth of the relation between the pupal period and tempera¬ 
ture is in all probability not nearly so closely shown by the figures 
as is that between 
the incubation period 
and temperature by 
the figures in Table 
I, since the impor¬ 
tant factor of amount 
and condition of 
food has had oppor¬ 
tunity to have its 
full effect. This fac¬ 
tor, next to temper¬ 
ature, is probably 
the most important 
single factor influ¬ 
encing the duration 
of the stage, espe¬ 
cially under the unnatural condition of the breeding cage. 
The figures of Table V are expressed in graphic form in figure 15. 
THE COCOON 
As stated, the larva usually begins its cocoon shortly after having 
finished feeding. Before starting its spinning it pushes the remains of 
its host to one end of the host cocoon and then accommodates its own 
cocoon to the size and shape of the space remaining within that of the 
host. The parasite cocoon therefore varies considerably in shape. It is 
usually, however, about one-half inch in length, about a third as broad. 
PUPAL PEP/OD - DArS 
Pig. 15.—Diagram showing relation between pupal period of Calliepht- 
altes sp. and temperature. The dot-and-dash line is the curve of 
average temperature, while the dotted line represents the female 
curve superimposed on that ot the males at Vienna, Va,, 1912. The 
greater tendency of the males to delay transformation to the adult 
stage is shown by reierring the male and female to the line of average 
temperatures. 
