BIOXOaIICS OF THE CHINCH BUG. 
Table 2. — Length of incubation period of eggs of Blissus U ucopterus, Columbia, 
S. C. 1919-20. 
Eggs deposited. 
Eggs hatched. 
Eggs deposited. Eggs hatched. 
Length 
of egg 
Length 
of egg 
Date. 
Num- 
ber. 
Date. 
Num- 
ber. 
stage. Date 
Num- 
ber. 
Date. 
Num- 
ber. 
stage. 
!• 
Da vs. 
Days. 
May 4 
3 
Mav 29 
3 
25 June 1 
June 1 
8 
16 
May 6 
6 May31 
1 
25 
June 18 
1 
17 
i June 1 
3 
26 June 2 .-. 
33 June 17 
14 
15 
1 June 2 
2 
27 
■ June IS 
12 
16 
May 8 
103 Mav 31 
12 
23 
June 19 
2 
17 
June 1 
43 
24 
June 20 
2 
IS 
June 2 
40 
25 June 3 
32 June 16 
1 
13 
June 3 
2 
26 
June 17 
3 
14 
June 4 
1 
27 
Junel* 
8 
15 
June 5 
2 
28 
June 19 
16 
16 
t June 6 
2 
29 
June 20 
1 
17 
June 7 
June 21 
1 
18 
Junes 
1 
31 
June 22 
2 
19- 
Hay 9 
9 June 2 
6 
24 June 4 
17 June IS 
4 
14 
June 3 
3 
25 
, June 19 
7 
15 
May 10 
37 June 2 
19 
23 
24 
25 
June 20 
5 
16 
June 3 
June 4 
14 
2 
June 21 
June 22 
1 
IS 
June 6 
June 5 
12 J 
1 
14 
2 
3 
26 
June 20 
Mavll 
21 June 2 
22 
June 21 
10 
16 
June 3 
June 4 
11 
5 
23 
24 
June 22 
June 23 
1 
18 
June 5 
June 10 
6 June 22 
June 23 
1 
4 
12 
June 6 
2 
26 
13 
May 12 
4S June 3 
4 
22 
June 24 
1 
14 
June 4 
2* 
23 June 11 
10 June23 
2 
12 
June 5 
11 
24 
June 24 
5 
13 
June6 
5 
25 
June 25 
3 
14 
Mav 13 
39 June 3 
1 
21 June 12 
9 June 24 
3 
12 
June 4 
8 
22 
June2S 
6 
16 
June 5 
12 
23 June 15 
11 June2S 
2 
13 
June 6 
IS 
24 
June 29 
7 
14 
May 17 
66 June 6 
14 
20 
Julyl 
2 
16 
June 7 
39 
21 June 19 
3 Julv 3 
3 
14 
June S 
13 
22 June 23 
7 July 6 
7 
13 
May IS 
2 June 9 
1 
22 June 26 
1 July 9 
1 
13 
June 10 
1 
23 June 27 
46 JulvlO 
44 
13 
May 19 
12 June 7 
12 
19 
Julv 12 
2 
15 
May 21 
3 June 12 
3 
22 June2S 
5 Julv 11 

13 
May 22 
2 June 12 
2 
21 
July 12 
3 
14 
May 25 
5S June 14 
IS 
20 July 1 
1 Julv 12 
1 
11 
June 15 
39 
21 Julv7 
14 Julvl6 
1 
9 
June 16 
1 
22 
Julv 17 
? 
10 
May 26 
22 June 14 
6 
19 
Julv IS 
11 
11 
June 15 
16 
20 JulvS 
6 Julv 20 
6 
12 
May27 
27 June 14 
1 
IS Julv 11 
12 Julv 23 
12 
12 
June 15 
23 
19 July 12 
14 Julv25 
13 
13 
June 16 
3 
20 
July 26 
14 
May 28 
IS June 15 
14 
IS Julv 24 
2 Aug. 4 
2 
11 
June 16 
4 
19 July 26 
5 Aug. S 
5 
13 
May 29 
23 June 15 
1 
17 July 27 
2 Aug. 5 
2 
9 
June 16 
22 
IS Aug. 21 
6 Sept. 5 
6 
15 
June 1 
11 June 16 
2 
15 
Total number of eggs, 664. Weighted average for the egg period, 21.96 + days. 
FERTILITY OF THE EGGS. 
Xot all of the eggs laid by the chinch bug are fertile. Fertility 
may depend upon the number of times the female has mated or upon 
whether or not the female has recently mated. The fact that the 
female lays infertile eggs at times may explain the necessity for 
frequent copulation, for should she mate only once or the mating 
interval, be too great, more of the eggs might be infertile. This, 
however, is somewhat conjectural and further observations on this 
point are necessary. In one instance -±0 eggs out of a total of 503, 
or about S per cent, were infertile. In another case 5 eo-crs out of 
