December, ’20] newcomer: winterkilling of codling moth 441 
papers be returned to the authors in order to reduce as far as possible 
the proceedings to those papers of real interest to all of the members 
of the Association. The Secretary was asked to return the papers thus 
set aside. 
f, 
Chairman A. L. Melander: This concludes the convention. We 
stand adjourned to meet at San Francisco, Cal., next year. 
Meeting adjourned. 
E. C. VanDyke, Secretary pro tem. 
PART II. PAPERS AND DISCUSSIONS 
Morning Session, June 17, 1920, 10.30 p. m. 
Chairman A. L. Melander: The regular papers for presentation 
and discussion will now be taken up. The first on the program is on 
“The Winterkilling of Codling Moth Larvae.” 
WINTERKILLING OF CODLING MOTH LARVAE 1 
By E. J. Newcomer, U. S. Bureau of Entomology, Yakima, Wash. 
It is a common experience in the spring to find “winter-killed” 
codling moth larvae. The writer, however, does not remember seeing 
any figures on the percentage of mortality resulting from different 
degrees of cold. Accurate figures could be secured only under con¬ 
trolled temperature conditions, but an opportunity has occurred 
recently of obtaining some interesting figures of mortality resulting 
from natural conditions. 
In Washington State, temperatures far below the normal were 
experienced during December, 1919, ranging in the Yakima and Walla 
Walla valleys from —14° to —36° F. At Yakima, on December 9 
and 10, there was a snowstorm with some wind, almost of the character 
of a blizzard, the temperature for the two days ranging between 7° 
and 16° F. The storm cleared &way on the 11th, the minimum tem¬ 
perature being 0°. For the succeeding four days, the temperatures 
were as follows: 2 
December 12 ' 13 14 15 
Maximum. 1 1 4 12 
Minimum. —22 —24 —18 —9 
During this period there were from 4 to 18 inches of snow on the 
ground. After December 15, the weather warmed up gradually, and 
1 Presented with permission of the Secretary of Agriculture. 
2 Figures taken from Climatological Data, U. S. Weather Bureau. 
