8 
BULLETIN 1016, U. S. DEPARTMENT OE AGRICULTURE. 
a total of 56. or about 9 per cent, were infertile, 
males were with the females at all times. 
In both instances 
NUMBER AND LENGTH OF 1NSTARS AND TOTAL LENGTH OF THE IMMATURE 
PERIOD. 
According to experiments conducted at the laboratory at Columbia, 
S. C. in 1919. and again in 1920. the nymphs of this species molt five 
times during their development from egg to adult, the same number 
of times as do the nymphs of the -squash bug (Anasa tristis De G.) 
and the harlequin cabbage bug {MurgaMtia histrionica Halm) . These 
species, although belonging to different families from the chinch 
bug, differ from this insect mainly in taxonomic characters rather 
than in their bionomics. There are indications that occasionally a 
nymph may molt only four times, as originally supposed, and very 
rarely six times. This, however, is the exception rather than the rule, 
and such variation is known to occur among larvae of various species 
of lepidopterous insects. 
Table 3. — Number and length of instars and total length of immature period of 
Blissus teucopterus. Columbia, S. C, 1919-20. 
Cage No. Nymph emerged. 
Date of first molt. 
Length of 
first 
instar. 
Date of second molt. 
Length of 
second 
instar. 
1 19-450 
19-4.54 
19-459 
19-462 
19-463 
19-466 
19-468 
19-473 
19-476 
19-478 
19-528 
3 20-700 
20-736 
20-747 
20-74S 
20-751 
July 11.. 
July 11.. 
July 16.. 
Julv 9.. 
July 10. 
JulvlO. 
JulvlO.. 
Julv 16. 
July 17. . 
Julv 17. 
July 26. 
June 11. 
June 15. 
June 15. 
June 15. 
June 12. 
Average. 
Julv 27. 
Julv 27. 
Julv 27. 
Julv IS. 
Julv 19. 
July 27. 
Julv 20. 
Julv 27. 
Julv 30. 
Julv 27. 
Aug. 1. . 
June 29. 
June 29. 
June 29. 
June 29. 
June 28. 
Days. 
Aug. 2. . 
Julv 31. 
Julv 31. 
Julv 24. 
Julv 26. 
Julv 31. 
Julv 27. 
Aug. 2. . 
Aug. 4. . 
Julv 31. 
Aug. 10. 
July 5. . . 
July 5. . . 
July 5. . . 
July 5... 
Julv 5. . . 
Days. 
12.75 
5. 75 
Nymph 
emerged. 
Date of 
Length of 
Date of 
Length of Date of fifth Length of 
Total 
length of 
inrmature 
period. 
Cage No. 
< third 
molt. 
third 
instar. 
fourth 
molt. 
fourth 
instar. 
molt 
(adult). 
fifth 
instar. 
, 
Days. 
Days. 
Days. 
Days. 
i 19-450 
Julv 11.... 
Aug. 10.... 
8 
Sept. 5 
26 
Oct. 4 
29 
85 
19-454 
Julv 11 
Aug. 9 
9 
Aug. 15 
6 
Sept. 5.... 
21 
56 
19-459 
Julv 16.... 
Aug. 9 
9 
Aug. 19.... 
10 
Sept. 17... 
29 
63 
19-462 
Julv 9 
Aug. 2 
9 
Aug. 13.... 
11 
Sept. 8.... 
26 
61 
19-163 
Julv 10.... 
Aug. 5 
10 
Aug. 15. ... 
10 
Aug. 31... 
16 
.52 
19-466 
Julv 10.... 
Aug. 8 
8 
Aug. 21.... 
13 
Sent. 20... 
30 
72 
- 19-468 
Julv 10.... 
Aug. 4 
8 
Aug. 21.... 
17 
Oct.9 
49 
91 
19-473 
Julv 16.... 
Aug. 9 
7 
Aug. 19. . . . 
10 
Sept. 5 
17 
51 
19-476 
Julv 17.... 
Aug. 7 
3 
Aug. 29 
22 
Oct. 4 
36 
78 
19-478 
Julv 17.... 
Aug. 7 
7 
Aug. 15 
• 8 
Sept. 16... 
32 
61 
19-528 
Julv 26.... 
Sept. 10. .. 
31 
Oct. 1 
21 
Oct. 28.... 
27 
94 
2 20-700 
June 11 
Julv 12.... 
7 
Julv 20 
8 
Aug. 3.... 
14 
53 
20-736 
June 15 
Julv 17 ... . 
12 
Aug. 8 
22 
Aug. 29... 
21 
75 
20-747 
June 15 
July 10.... 
5 
Julv 26 
16 
Aug. 5 
10 
51 
20-74S 
June 15 
Julv 9 
4 
Julv 19 
10 
Aug. 11... 
23 
ot 
20-751 
June 12.... 
Average. 
Jul}- 12.... 
7 
Julv 29 
17 
Aug. 14. . . 

16 
63 
9 
14. 12+ 
24.56+ 
66.43 
1 
1 19 refers to the year 1919. 
1 20 refers to the year 1920. 
