U. S. D. A., B. E. Bui. 80, Part VI. D. F. 1. 1., 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 larvae of the 

 two broods, and also a comparison of relative occurrence of larvae 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. 



30490°— Bull. 80—12 6 71 



