U.S. D. A., B. E. Bul. 80, Part VI. D. F.1.1., Issued November 28, 1910. 
PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
LIFE HISTORY OF THE CODLING MOTH IN NORTHWEST- 
ERN PENNSYLVANIA. 
By A. G. Hammar, 
Engaged in Deciduous Fruit Insect Investigations. 
INTRODUCTION. 
In 1907 the section of deciduous fruit insect investigations of the 
Bureau of Entomology established at North East, Pa., a temporary 
field station, for the investigation of certain orchard and vineyard 
pests. One of these, the codling moth (Carpocapsa pomonella L.), has 
been studied for the three consecutive years of 1907, 1908, and 1909. 
The rearing work during the first two seasons covered only the more 
important features in the development of the insect, while in 1909 
efforts were made to rear the insect throughout the seasons and to 
determine the time and relative occurrence of the various stages of 
the two broods. 
In 1907 the work was carried out by Mr. P. R. Jones of this Bureau, 
and in 1908 and 1909 by the writer, who during the last season was 
assisted by Mr. Edwin Selkregg, of North East, Pa. Mr. Fred John- 
son, of this Bureau, has for the three seasons contributed to this 
work numerous field observations. All of these studies have been 
made under the direction of Mr. A. L. Quaintance, in charge of de- 
ciduous fruit insect investigations. 
In the presentation of the life-history studies the separate stages 
of the two generations are first considered in detail as observed in 
1909. Later are described certain fluctuations, found in regard to 
the time of emergence of moths, the time of maturity of larvee of the 
two broods, and also a comparison of relative occurrence of larve of 
the two broods for the three seasons under consideration. 
The term “brood” is here used in speaking of individuals of one 
generation of any stage, as egg, larva, or pupa. A generation 
naturally includes all the stages of the life cycle, and is considered 
to begin with the egg stage and to terminate with the moth or imago 
stage of the same generation. 
71 
