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



PLATE VI. 



Fig. 1. — Section of lead showing the branched minings and 

 mandibular impressions of two beetles. This was the 

 underside of the second layer of lead, which was rolled 

 unevenly and permitted the light to penetrate; thus the 

 minings were irregular. Enlarged 1| times. (Table 2, 

 No. 4.) Photograph by E . D. Hartman. 



Fig. 2. — First layer of tin-coated lead down after bein 

 removed from infested section, showing 58 attempt! 

 of which 24 were successful, in penetrating at leas 

 the first thickness . In many cases where the beetle 

 attempted to escape between the section and th 

 lead, they mined more in the lead than those tha 

 penetrated several thiclcnesses . One-fourth naturi 

 size. (Table 2, No. 52.) Photograph by R. I 

 Hartman . 



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Fig. 3. — Typical beetle mine or single exit burrow 

 in lead sneathing, enlarged 6i times. Beetle had 

 mined about two-thirds through the sheathing. 

 Photograph by R. D. Hartman. 



Fig. 4. — First layer of sheet zinc after being removed fro 

 infested section, showing 31 attempts, of which 2 w£ 

 successful, in penetrating one thiclniess. These are des: 

 nated by arrows. Three-tenths natural size. (Table i 

 Photograph by R. D. Hartman. 



THE LEAD-CABLE BORER. 



