BULLETIN OF THE 



No. 189 



Contribution from the Bureau of Entomology, L. O. Howard, Chief 

 April 12, 1915. 



STUDIES OF THE CODLING MOTH IN THE CENTRAL 

 APPALACHUN REGION. 



By F. E. Brooks and E. B. Blakeslee, 

 Entomological Assistants, Deciduous Fruit Insect Investigations, Bureau of Entomology . 



CONTENTS. 



Introduction 1 



Localities in which investigations were made. 2 



Nature and extent of the investigations 2 



Explanation of the use of terms 3 



Investigations at CharlottesvOle, Va 4 



Investigations at Greenwood, Va 11 



Investigations at Hage^sto^vn, Md 13 



Investigations at Winchester, Va 21 



Investigations at Fishersville, Va 28 



Investigations at French Creek, W. Va 32 



Investigations at Pickens, W. Va 37 



R&um6 of rearing experiments in Maryland, 



Virginia, and West Virginia 40 ' 



Number of first-brood larvae transforming 



first season 42 



Effect of differences in altitude and latitude 



upon the development of the codling moth. 42 

 Relative niunbers of larvse ascending and 



descending the trees 44 



Seasonal effect of weather conditions on the 



different stages of the codling moth 45 



Cannibalism among codling-moth laxvse 45 



Natural enemies 46 



Summary 48 



INTRODUCTION. 



In many localities throughout the central Appalachian region the 

 recent rapid development of the apple-growing industry has made 

 the control of the codhng moth (Carpocapsa pomonella L.) a subject 

 of special and increasing interest. The hilly or mountainous nature 

 of the land has led to the location of orchards at elevations ranging 

 from a few hundred feet to more than 4,000 feet above the level of 

 the sea. The great diversity of temperature that occurs between the 

 lower and the more elevated orchards has a marked effect on tho 

 time of transformation of the (lifTerent stages of the codling moth, 

 and coTLScrjuently has direct bearing on the relative number and tho 

 destructivcness of second-brood larvae. 



In tho spring of 1911 tho Bureau of Entomology began a study of 

 the codling uiotli in tiie region just mentioned, as a part of its inves- 



77013-— Bull. 189—15 1 



