104 
Journal of Agricultural Research 
Vol. XIV, No. 2 
Table I— First and last bom generations , date of birth, reproductive period in days , 
daily average and total number of young , total length of life, and maximum and minimum 
temperature during which each generation of Toxoptera graminum lived. Columbia , 
S. C ., 1913-1915—* Continued 
series a— continued 
Generations. 
First¬ 
born. 
59 
60 
61 
62 
63 
64 
65 
66 
Last- 
born. 
a 18 
Dates. 
1914. 1914. 
Sept. 17 to Oct. 10, 
23 to 28, 
Oct. 3 to Nov. 14. 
8 to 6. 
10 to 26. 
10 to Dec. 2. 
36 to 17. 
1915- 
Nov. 12 to Jan. 18. 
Dec. 2 to Feb. 3. 
Repro¬ 
ductive 
period. 
Days. 
16 
24 
28 
o 
6 
32 
28 
4 i 
14 
Young. 
Daily- 
average. 
2 . 68 
2. 45 
2 - 35 
. 00 
3 - 33 
1. 56 
1. 42 
92 
28 
Total. 
47 
59 
66 
o 
20 
5 ° 
40 
37 
18 
Length 
of life. 
Days. 
23 
35 
42 
29 
47 
44 
48 
67 
63 
Temperature. 
Maxi¬ 
mum. 
9 F. 
88 
86 
86 
86 
86 
81 
81 
75 
65 
Mini¬ 
mum. 
F. 
51 
34 
34 
34 
5 i 
22 
21 
21 
21 
67 
68 
69 
70 
7 1 
* 9 * 5 - 
Jan. 18 to Feb. 26 
Feb. 25 to Apr. 27 
Apr. 7 to May 16 
30 to June 9 
May 25 to May 31 
1 
20 
16 
1 
o 
2. 00 
3.10 
•37 
1. 00 
. 00 
2 
62 
6 
1 
o 
39 
61 
39 
40 
6 
72 
89 
92 
93 
93 
27 
30 
44 
56 
58 
SERIES B 
1914. 1914 
I 
Mar. 
23 to May 
12.. 
25 
2. 72 
68 
50 
92 
3 1 
2 
Apr. 
3 to 
24.. 
23 
3-30 
76 | 
5 i 
96 
37 
3 
16 to 
25.. 
23 
2. 73 
63 
39 
96 
40 
4 
26 to 
x 5 - • 
IO ; 
2.30 
23 
19 
92 
S 2 
2 
27 to June 
3 -- 
21 
2. 66 
37 
96 
52 
5 
May 
4 to May 
I 5 - • 
2 
4. 00 
8 
11 
92 
52 
6 
12 to June 18.. 
16 
5. 00 
80 
37 
99 
55 
7 
20 to 
21.. 
25 
2. 16 
54 
33 
99 
55 
8 
26 to 
29.. 
14 
4 . 57 
64 
34 
103 
60 
3 
29 to 
26.. 
II 
4. 00 
44 
28 
103 
60 
9 
June 
2 to July 
9.. 
18 
2. 60 
47 
37 
103 
60 
10 
8 to 
3 -- 
8 
4 - 75 
38 
25 
103 
60 
11 
13 to 
11.. 
20 
i -45 
29 
28 
103 
60 
12 
21 to 
i<r. . 
Q 
4. 11 
24 
103 
62 
4 
22 to 
l6. . 
7 
IS 
T* 
2. 40 
O / 
36 
24 
O 
103 
62 
13 
29 to Aug. 
4. . 
27 
I. 29 
35 
36 
100 
61 
14 
July 
6 to 
8. . 
22 
I. 8l 
40 
33 
102 
61 
5 
11 to July 
29. . 
9 
2.88 
26 
18 
102 
67 
*5 
13 to Aug. 
17.. 
25 
I. 80 
45 
35 
102 
61 
16 
20 to 
22.. 
20 
2. 15 
43 
33 
102 
61 
*7 
29 to Sept. 
4.. 
28 
2. 42 
68 
37 
94 
68 
6 
29 to 
2. . 
l6 
3 - OO 
48 
35 
94 
68 
18 
Aug. 
5 to 
8.. 
22 
2. 50 
60 
34 
94 
66 
19 
11 to 
10.. 
19 
3-36 
64 
30 
94 
63 
20 
17 to 
8.. 
15 
3 -S 3 
53 
22 
94 
63 
7 
18 to 
22.. 
*3 
4. OO 
52 
35 
94 
39 
21 
24 to 
25. . 
27 
2 . II 
57 
32 
94 
39 
22 
28 to Oct. 
7 -- 
26 
I. 84 
48 
40 
94 
39 
a Oviparous female. 
