UNITED STATES DEPARTMENT OF AGRICULTURE 



In cooperation with the 

 Washington Agricultural Experiment Station 



DEPARTMENT BULLETIN No. 1235 



Washington, D. C. 



November 28, 1924 



LIFE HISTORY OF THE CODLING MOTH IN THE YAKIMA YALLEY OF 



WASHINGTON.' 



By E. J. Newcomer, Entomologist, and W. D. Whitcomb, Assistant Entomologist, 

 Fruit Insect Investigations, Bureau of Entomology. 



CONTENTS. 



Introduction 1 



The Yakima Valley 2 



Definitions of terms 4 



Methods and rearing apparatus employed in 



the life-history studies 4 



The insectary 6 



Seasonal-history studies of 1919 6 



Codling moth band studies of 19191 20 



Seasonal-history studies of 1920 22 



Codling moth band studies of 1920 35 



Seasonal-history studies of 1921 37 



Page. 



Codling moth band studies of 1921 53 



Variations in the seasonal history of the cod- 

 ling moth in the upper and lower Yakima 



valleys 55 



Seasonal-history studies at Wenatchee, 



Wash, 1915-16 56 



Miscellaneous studies 58 



Review of seasonal history of the codling 



moth in 1919, 1920, and 1921 72 



Summary 73 



INTRODUCTION. 



The codling moth, Carpocwpsa pomonella L., is the most serious 

 insect pest with which the apple growers of Washington have to con- 

 tend. Previous to 1915, little trouble had been experienced in con- 

 trolling this pest, but in the years 1915 to 1918, inclusive, losses from 

 wormy apples increased, more difficulty being experienced in the re- 

 gion about Yakima than in the other important apple-growing regions 

 of the State. This led the Bureau of Entomology, United States 

 Department of Agriculture, at the request of the department of agri- 

 culture of the State, to establish a field station at Yakima, in the 

 spring of 1919, for the purpose of making a careful study of the 

 codling moth in Washington. 2 



1 With notes on the life history in the Wenatchee Valley of Washington. 



8 The work was done under the direction of Dr. A. L. Quaintance, in charge of Fruit Insect Investigations, 

 Bureau of Entomology, in cooperation with the Washington Agricultural Experiment Station. The 

 senior author was placed in immediate charge of the work at Yakima, and was assisted throughout the 

 investigations by the junior author. During the summer of 1920, Miss Sadie E. Keen, now with the Bureau 

 of Entomology, assisted temporarily with the life-history investigations. Valuable assistance and in- 

 formation were given at various times by members of the Washington State department of agriculture, 

 particularly by those located at Yakima in the capacity of horticultural inspectors. 



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