U, S. D: A., B. B. Bul.'97, Part 11. DB. YT. D.; April 1; 1907. 
PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
LIFE HISTORY OF THE CODLING MOTH AND ITS CONTROL 
ON PEARS IN CALIFORNIA. 
By 8S. W. Foster, 
Agent and Expert, Deciduous Fruit Insect Investigations. 
INTRODUCTION. 
The codling moth (Carpocapsa pomonella I.) in California presents 
certain differences in its life history as compared with what is true 
for the East, principally a lengthening of the respective stages, 
due to a lower mean temperature during their period of development, 
especially in the first generation. As remedial measures can only 
be properly prescribed when based on a complete knowledge of the 
insect to be controlled, such observations as were possible on the life 
history of the insect in the vicinity of Walnut Creek were made during 
the seasons of 1909 and 1910. These, with field notes from other 
sections during 1910, are given in the following pages. For com- 
parison, and also to further supplement the writer’s own observa- 
tions, some data from San Jose, Cal., are included, as secured by Mr. 
F. L. Young, of the Bureau of Entomology, working under the direc- 
tion of Mr. P. R. Jones. 
The pear crop of California suffers much from injury by the codling 
moth, and in view of the commercial importance of this crop, the 
losses represent in the aggregate a large item. The injury is espe- 
cially important 6n green fruit destined for shipment to eastern 
markets, but even in the case of drying stock there is without doubt 
an important deterioration in quality. The results of experiments 
reported in this paper show that much may be done to lessen this 
damage by two or three timely applications of poison sprays, and it 
is hoped the recommendations may prove of value to California pear 
growers. : 
The writer desires to acknowledge the assistance of Mr. EK. J. 
Hoddy, formerly of this bureau, in helping with part of the spraying 
experiments and in taking results. Also, to express thanks to 
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