Jan. 12,1924 
Effect of Cold Storage on Bean Weevils 
103 
EFFECT OF 32 DAYS’ REFRIGERATION ON SUBSEQUENT EMERGENCE OF 
ADULTS 
'Hie emergence of adults from three of these small lots after 32 days 
exposure to 20°, 32°, and 39° F. is shown m Table IIL 
Table lU.-Emergence of Bruchus quadrimaculatus from black-eye cowpeas refrigerated 
32 days 
Temperature 
of refrigera¬ 
tion. 
Interval 
between 
removal 
from cold 
storage 
and exam¬ 
ination. 
°F. 
Days . 
20 . 
7 
20 . 
16 
20 . 
23 
20 . 
3 i 
20 . 
52 
20 . 
75 
32 . 
7 
32 . 
16 * 
32 . 
23 
32 . 
3 i 
32 . 
52 
32 . 
75 
Number of weevils 
emerged. 
Male. 
O 
O 
O 
O 
O 
O 
O 
O 
O 
O 
o 
o 
Female. 
O 
O 
O 
O 
o 
o 
o 
o 
o 
o 
o 
o 
Total. 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
Temperature 
of refrigera¬ 
tion. 
°F. 
39. 
39. 
39. 
39. 
39. 
39-• 
Control 
Do. 
Do. 
Do. 
Do. 
Do. 
Interval 
between 
removal 
from cold 
storage 
and exam¬ 
ination. 
Days . 
7 
16 
23 
31 
52 
75 
7 
16 
23 
3 i 
52 
75 
Number of weevils 
emerged. 
Male. 
2 
O 
2 
O 
O 
O 
7 
10 
7 
25 
i 21 
Female. 
29 
1 
o 
2 
O 
O 
O 
6 
4 
8 
14 
19 
21 
Total. 
3 
o 
4 
o 
o 
o 
13 
14 
15 
39 
40 
50 
The data in Table III indicate that 32 days of refrigeration at 20° or 32° 
F. will kill all forms, but that a longer time at 39 is necessary 
all infestation within the cowpeas. 
EFFECT of low TEMPERATURES on immature stages of WEEVILS 
These low temperatures cause a dark spot to appear in the middle of 
Jdorsal TegS P of the tan*. As this spot enlarges it b^omes sur¬ 
rounded by a lighter band, and when approximately the middle one 
fourth of the dorsal region becomes discolored the tissues beneath the 
integument soften and the larva dies. The same signs of injury can be 
observed in young pupae. 
EFFECT OF REFRIGERATION ON LARV 2 E, PUPA 5 , AND UNEMERGED ADULTS 
As previously noted, a small lot of cowpeas was removed from each 
bae in refrigeration at the time of each examination. Some of these 
were dissected a few days after refrigeration; others were kept as long 
as seven months. Table IV gives the data obtained by the dissection 
of these samples. The dissection of 13 cowpeas four days after remov- 
invthon^rorn refrigeration at 20° F. for 11 days showed 20 per cent 
of weevils to be alive, but the other 37 cowpeas of^the same sample 
subsequently produced no adults. This indicates that although 20 F. 
does not kiU all the unemerged weevils immediately, it injures them 
<511 an extent that they die before emerging. 
The indications of the foregoing data are that weevils emerge from 
cowpeas refrigerated at 39° F. for n and iS d XVXuSi Sis ^ 
not after exposure to this temperature for 2 3 days (though this 
