THE GRANARY WEEVIL. 
Table 6. — Duration of the pupal stage of the granary weevil 
27 
Date of— 
Length 
pupal 
Mean tem- 
peratures 
No. 
Date of— 
Length 
pupal 
Mean tem- 
peratures 
No. 
Pupa- 
Emerg- 
stage 
Maxi- 
Mini- 
Pupa- 
Emerg- 
stage 
Maxi- 
Mini- 
tion 
ence 
mum 
mum 
tion 
ence 
mum 
mum 
- 
1919 
Days 
°F. 
°F. 
1920 
Days 
°F. 
°F. 
1 
Oct. 25 
Oct. 30 
5 
91 
66 
24 
Oct. 10 
Oct. 16 
6 
88 
58 
2 
Nov. 1 
Nov. 6 
5 
86 
66 
25... 
Nov. 10 
Nov. 18 
8 
74 
57 
3 
Oct. 27 
Nov. 1 
5 
91 
67 
4 
Nov. 1 
Nov. 6 
5 
86 
66 
1921 
5 
Nov. 10 
Nov. 17 
7 
81 
59 
26 
Jan. 3 
Jan. 13 
10 
79 
52 
27 
Jan. 7 
Jan. 16 
9 
75 
48 
1920 
28 
Jan. 15 
Jan. 31 
16 
75 
48 
6 
Apr. 26 
May 3 
7 
86 
64 
29 
Jan. 12 
Jan. 22 
10 
77 
49 
7 
Aor. 30 
May 6 
6 
88 
62 
30 
Jan. 29 
Feb. 12 
14 
79 
53 
8 
Apr. 28 
May 4 
6 
85 
61 
31 
Feb. 3 
Feb. 13 
10 
79 
54 
9 
Apr. 29 
May 5 
6 
87 
61 
32 
Feb. 12 
Feb. 23 
11 
80 
47 
10 
May 9 
May 15 
6 
89 
62 
33 
Mar. 3 
Mar. 18 
15 
78 
59 
11 
May 12 
May 18 
6 
88 
65 
34 
Mar. 13 
Mar. 23 
10 
90 
61 
12 
May 13 
...do..... 
5 
88 
66 
35 
...do.... 
Mar. 21 
8 
91 
62 
13 
May 19 
May 24 
5 
88 
63 
36 
Mar. 28 
Apr. 5 
8 
85 
62 
14 
July 16 
July 22 
6 
93 
71 
37 
Mar. 25 
Apr. 2 
8 
87 
63 
15 
Aug. 3 
Aug. 10 
7 
91 
70 
38 
...do.... 
Apr. 1 
7 
87 
63 
16 
July 26 
Aug. 1 
6 
92 
70 
39 
Apr. 4 
Apr. 10 
6 
89 
60 
17 
Aug. 14 
Aug. 21 
7 
93 
69 
Mean 
18 
Aug. 9 
Aug. 15 
6 
94 
70 
40 
Aug. 28 
Sept. 3 
6 
82 
19 
Aug. 19 
Aug. 25 
6 
95 
69 
41 
. -do.... 
Sept. 2 
5 
82 
20 
Aug. 21 
Aug. 27 
6 
95 
69 
42 
Aug. 29 
Sept. 3 
5 
84 
21... 
Sept. 1 
Sept. 6 
5 
93 
70 
43 
Sept. 17 
Sept. 22 
5 
77 
22. 
Sept. 28 
Oct. 3 
5 
82 
60 
44 
Oct. 31 
Nov. 7 
7 
68 
23 
Sept. 30 
Oct. 6 
6 
81 
59 
These data indicate that during the warm season of the year, when 
the mean temperatures vary from a maximum of 85° to 95° F. to a 
minimum of 61° to 71° F., the pupal stage may require a minimum 
of 5 days for development. During the hottest summer weather 
pupal development was completed in from 5 to 7 days. Certain 
pupae completed their development in 5, 6, and 7 days when the 
mean temperature was 77°, 82°, and 68° F., respectively. During 
the colder season six pupae completed their development in 16, 10, 
14, 10, 11, and 15 davs when the mean temperatures were 61.5°, 63°, 
66°, 66.5°, 63,5°, and 68.5° F., respectively. 
