UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 8 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



August 9, 1920 



ROUNDHEADED APPLE-TREE BORER 1 : ITS LIFE 

 HISTORY AND CONTROL. 



By Fred E. Brooks, Entomologist, Deciduous Fruit Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



History 2 



Distribution 2 



Food plants 3 



Distribution as affected by native host 



plants 4 



Character of injury 5 



Methods used in securing breeding 



material and rearing the insects- 6 

 Cages used for rearing and observing 



borers 6 



Page. 



The egg and oviposition 7 



The larva 11 



The pupa 14 



The adult , 15 



Seasonal phenomena of the host trees, 

 as an index to the time of develop- 

 mental changes of the insect 27 



Natural enemies 29 



Methods of control 30 



Summary 39 



Literature cited 41 



INTRODUCTION. 



In the spring of 1911 a field station of the Bureau of Entomology 

 was established at French Creek, W. Va., and a study begun of the 

 roundheaded apple-tree borer in connection with a general project 

 on boring insects attacking deciduous fruit trees. The work was 

 under the direction of Dr. A. L. Quaintance and was placed in 

 charge of the writer, with whom was associated, in 1911 and 1912, 

 E. B. Blakeslee, of the Bureau of Entomology. During the sum- 

 mers of 1915, 1916, and 1917 C. R. Outright was employed tempo- 

 rarily to assist with the investigation. 



The field station is located in a hilly, partly wooded region where 

 small orchards, wild seedling apple trees, and native host trees of 

 the borer abound and where the insect itself is plentiful. For rearing 

 purposes and the testing of control measures, 1,000 3-year-old apple 

 trees, of the varieties known as King, Grimes, and York Imperial, 

 were planted in the adjacent locality of Elkins, W. Va., on land 

 leased for the purpose. In addition to the work at the two points 

 mentioned, rearing and life-history studies were conducted at Pick- 

 ens, Weston, and Great Cacapon, W. Va., and at Demorest, Ga., 



1 Saperda Candida Fabr. 

 154187°— 20— Bull. 847 1 



order Coleoptera, family Cerambycidae. 



