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



PLATE VIII. 



Fig. 1. — Two sections showing 

 exit holes through varnished 

 and painted areas. ^= var- 

 nished section, to two-thirds of 

 which was applied, at intervals 

 before emergence, 5 coats of 

 spar varnish. Forty-six beetles 

 emerged through varnished area 

 and 11 in unvarnished portion. 

 £= white-paint enamel section, 

 to three-fourths of which was 

 applied one good coat of this 

 paint. Thirty-seven beetles 

 emerged through the painted 

 area and 18 through the un- 

 painted portion. These experi- 

 ments, as in most cases, gave no 

 material check to the beetles' 

 emergence. One-half natural 

 size. (Table 4, Nos. 5 and 12.) 

 Photograph by R . D . Hartman. 



Fig. 2.— First thickness of lead 

 sheathing after being removed 

 from infested section. Previ- 

 ous to the lead being wrapped 

 around the section about one- 

 half of undarside (A) was given 

 5 coats of spar varnish and 3 

 coats on infested section. Be- 

 sides these numerous coats of 

 varnish some beetles were able 

 to penetrate 5 thicknesses of 

 No. 3 lead and emerge. Two- 

 fifths natural size. (Table 3, 

 No. 56.) Photograph by R. D. 

 Hartman 



Fig. 3. — First two thicknesses of the three treated lead sheathings after being removed from infested 

 section and manner in which beetles stopped as successive thicknesses were reached. Upper, 

 embedded carborundum, where 17 beetles started in first thickness and 14 reached the second. 

 Middle, tin-coated section, where 14 started in the first and 6 reached the second thickness. 

 Lower, copper-coated section, with 16 and 12 penetrations, resnectively. One-flfth natural size. 

 (Table 2, Nos. 54, 54c, 54b.) Photograph by R. D. Hartman. 



