664 
Journal of Agricultural Research 
Vol.V, No. is 
Temperatures ranging from 33 0 to 34 0 did not prove entirely fatal 
to the first-instar larvae until the seventeenth day of refrigeration; one 
larva out of 763 was alive on the sixteenth day. This was very excep¬ 
tional and demonstrates the value of using an abundance of material 
and of continuing examinations after all larvae seem to have been killed. 
Only 4 out of 1,446 were alive after 10 days of refrigeration; 1 out of 
215 after 12 days, and 2 out of 632 after the thirteenth day of refrigera¬ 
tion. First-instar larvae to the number of 1,256, removed after the 
seventeenth, eighteenth, and nineteenth days of refrigeration, were all 
dead. No second-instar larvae subjected to 33 0 to 34 0 were found alive 
after the tenth day of refrigeration; 1,997 removed after n to 19 days 
of refrigeration were all dead. A few third-instar larvae subjected to 
33 0 to 34 0 lived until the fifteenth day of refrigeration, but none for a 
longer time. After the ninth day no larvae were found alive, except 
during the examinations made after the eleventh and the fifteenth days 
of refrigeration, when 4 out of 126 and 3 out of 154, respectively, were 
found alive. A study of the data in Table I shows that a temperature 
of 34 0 to 36° had practically the same effect upon 1,615 larvae as did, 
that of 33 0 to 34 0 . 
A temperature of 36° proved fatal to first-instar larvae after the tenth 
day. After the ninth day of refrigeration 1 out of 476 was found 
alive. No living first-instar larvae out of 3,272 were found alive after 
refrigeration from 10 to 15 days. The mortality at this temperature 
among first-instar larvae became very noticeable after the sixth day of 
refrigeration, when 57 out of 132 larvae were found dead. No second- 
instar larvae were found alive after the eighth day of refrigeration; thus, 
all of 2,508 removed after refrigeration from 8 to 16 days were found 
dead. No third-instar larva was found alive after the ninth day of 
refrigeration, except on the fourteenth and fifteenth days, when 1 living 
larva was found out of 262 and 199 larvae examined. After the ninth 
day but 2 out of 404 larvae were found alive. 
Temperature, 36° to 40° F.: No examinations were made to deter¬ 
mine the effect of this temperature on the first-instar larvae until after 
the tenth day of refrigeration. Of 339 larvae removed after refrigeration 
from 11 to 20 days, none was alive. No living second-instar larva was 
found alive after the eighth day of refrigeration; after the seventh day 
18 out of 112 were found alive. All of 868 second-instar larvae removed 
after refrigeration from 8 to 20 days were dead. No living third-instar 
larva was found after refrigeration for 10 days, 3 out of 115 being 
alive after refrigeration for 9 days. All of 1,989 larvae removed after 
refrigeration from 11 to 18 days were dead. 
Temperature, 38° to 40° F.: All of 279 first-instar larvae removed 
from storage after refrigeration from 16 to 30 days were dead, 15 out of 
61 being alive after refrigeration for 15 days. No living second-stage 
larva was found after refrigeration from 20 to 28 days. No examina- 
