UNITED STATES DEPARTMENT OF AGRICULTURE 



4*i>- 



M BULLETIN No. 1107 |« 



Washington, D. C. 



PROFESSIONAL PAPER 



December 4, 1922 



THE LEAD-CABLE BORER OR " SHORT-CIRCUIT 

 BEETLE" IN CALIFORNIA. 1 



By H. E. Burke, 2 Entomologist, R. D. Hartman, Field Superintendent in Insect 

 Control, and T. E. Snyder, Entomologist, Forest Insect Investigations, Bureau 

 of Entomology. 



CONTENTS. 



Page. 

 Review of injury to metals by boring 



insects throughout tbe world 1 



Injury to lead fuses by insects 3 



Damage to lead sheathing of aerial 



cables by ScoMcia declivis Lee 4 



Damage by the California lead-cable 

 borer {Scobicia declivis) to trees and 



forest products 9 



Biology of Scobicia declivis 11 



Distribution 11 



Food plants 12 



Associated insects 12 



Predatory and parasitic enemies 12 



Life cycle 13 



Seasonal history A 



Description and habits 14 



Control experiments 20 



Tests at Falls Church, Va., 1918 



and 1919 20 



Results of experiments at Falls 



Church, Va., 1918 and 1919___ 21 

 Tests at Los Gatos, Calif., 1918- 



1920 21 



Page. 



Control experiments — Continued. 



Results of experiments at Los 

 Gatos, Calif., 1918-1920 , 23 



Experiments in California during 

 the season of 1921 30 



Results of experiments in Cali- 

 fornia in 1921 30 



Results of experiments in Cali- 

 fornia in 1922 39 



The metal-penetrating ability of 

 the insects associated with the 



cable borer 40 



Summary and conclusions 41 



Literature cited 42 



Insects attacking or penetrating 

 metals ; 42 



The California lead-cable borer 



(ScoMcia declivis) 46 



Appendix 49 



Taxonomy and morphology of the 

 larval stages of Scobicia de- 

 clivis Lee. — Adam G. Boving 49 



Description of mature adult of Sco- 

 bicia declivis— R. h. Bartmari— 54 



REVIEW OF INJURY TO METALS BY BORING INSECTS THROUGH- 



OUT THE WORLD. 



From time to time articles appear in technical journals throughout 

 the world describing injury to metal by boring insects, such injury 

 occurring most commonly in the Tropics. Often the press makes 



"■Scobicia declivis Lee; order Coleoptera, family Bostrichidae. 



2 The authors' names are arranged alphabetically; R. D. Hartman should be credited 

 with the biological studies and most of the experimental tests in California. 



2047—22 1 1 



