Bui. 1107, U. S. Dept. of Agriculture. 



Plate VII. 



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Fig. 1. — Method of wrapping infested oak with 

 lead sheathing to determine number of thick- 

 nesses beetles are able to penetrate in emerging. 

 Larval mines in wood and emergence holes of 

 beetles in end of section. (Table 2, No. 55a.) 

 Photograph by H. E. Burke. 



Fig. 2. — Infested section of oak 

 wrapped with lead alloy to de- 

 termine number of thicknesses 

 o f lead penetrated by beetles in 

 emergence. Method of wrap- 

 ping also shown. (Table 3, 

 No . 62 . ) Photograph by H . E 

 Burke. 



Fig. 3.— Work of beetle and larvae 

 in infested section of live oak. 

 Larval mines and egg galleries. 

 Longitudinal section. Photo- 

 graph by H. E. Burke. 



Fig. 4. — Cross section of infested oak, showing how the 

 beetles sometimes emerge at the end of a section. Piles 

 of dust indicate the work of the associated larvae of the 

 powder-post beetle Lyctus vlankollis. Photograph by 

 H.E.Burke. 



THE LEAD-CABLE BORER. 



