IOO 
Journal of Agricultural Research 
Vol. XXVII, No. a 
fluctuations of a few degrees. Cotton sample bags were filled with from 
3,000 to 5,000 infested beans each, obtained from commercial storage, 
and these were removed at intervals and mailed to the laboratory at 
Alhambra, Los Angeles County, Calif. The time spent in transit was 
sufficient for the insects not killed to become active. 
A short time after they were received at the laboratory the beans were 
counted and a sample of 200 taken at random from each sack. These 
were dissected and all weevils found—larvae, pupae, and unemerged 
adults, both alive and dead—were recorded. Subsequent examinations 
of the sacks of beans were made at various times. 
RESULTS WITH STORAGE AT 32 0 F. 
Eleven samples of beans were exposed at 32 0 F. for periods ranging 
from 7 to 61 days. When the sacks were opened numerous emerged adult 
weevils were found. Among the 43,281 beans in the 11 samples, 5,649 
adults were counted, 5,272 dead and 377 alive. No live adults occurred 
in samples refrigerated for 46, 56, or 61 days. Samples exposed for 7, 14, 
22, 28, and 31 days contained sufficient live emerged weevils to reinfest 
the seeds. Although the condition of the emerged insects found is a 
rough index of the effect of the various exposures, it is necessary to refer 
to die results of subsequent examinations in order to ascertain the ability 
of the insects which survived within the beans to perpetuate the infesta¬ 
tion. 
At the time of the first examination, all emerged weevils were removed 
from the sacks. Reexaminations showed that some of the larvae, 
pupae, and adults which were alive within the beans at that time were 
able to emerge, following exposure to laboratory temperatures favorable 
to growth and reproduction. Heavy reproduction took place in beans 
refrigerated for 7 days, and live weevils were found in sacks subjected 
to 14 and 28 days of cold storage at 32 0 F. 
The living weevils taken from a number of the samples at the first 
examination were placed under conditions favorable for reproduction, and 
it was found that adults from samples refrigerated 14 days or more were 
very weak and seemed to have lost much of their vitality; those from 
beans stored 22 days or longer failed to deposit eggs. Six other samples, 
not included in the tabulations given in this report, were exposed to 32 0 F. 
for 66 days and all emerged weevils were found to be dead. These samples 
were estimated to contain 20,500 beans and 43,700 weevils. A later 
inspection showed that this exposure had completely killed the infesta¬ 
tion. 
Table I gives the results of the dissection of 200 beans from each of 
the refrigerated sacks. A total of 2,200 beans dissected to represent 
the average condition of the 11 samples contained 2,360 weevils; 1,324 
(56 per cent) of them were larvae; 630 (27 per cent) were pupae, and 406 
(17 per cent) were adults which had not emerged from the pupal cells. 
The percentages of all forms killed after different periods of refrigeration 
are seen to be not very consistent with the increasing mortality to be 
expected with increasing exposure to cold. The samples were put in 
storage at two different times of year, November and February, and this 
seems to be related to the resistance of the insects, those subjected to 
refrigeration in November being less resistant than the others. The 
samples in which the mortality was 69.54, 71.48, and 97.20 per cent wpre 
