328 



YEARBOOK OF THE DEPARTMENT OF AGRICULTURE. 



The beetle which is responsible for this defect and the resulting 

 losses to the lumber interests of this country, amounting to millions 



of dollars, attacks the sapwood of the young, 

 living, healthy tree, in which the adults 

 excavate their brood galleries (fig. 43) and 

 deposit their eggs. These hatch and de- 

 velop into beetles, and emerge within one 

 year. The next year the operation is re- 

 peated in another place in the same tree, 

 and so on for hundreds of years, or as long 

 as the tree lives, so that the galleries exca- 

 vated in different years and periods occupy 

 their respective positions in the heartwood 

 and sapwood of the full-grown and old tree, 

 as shown in tig. 41. 



Nearly all the damage by this insect, as 

 affecting the best part of the trees, was 

 done 50, 100, 200, or, in some cases, as 

 noted in an old tulip tree, over 400 years 

 ago. The age of each gallery observed in 

 the end of the log is easily determined by 

 counting the number of annual layers of 

 r- wood between the old healed-over entrance 

 beetle in sapwood of living tree, to the galleries and the bark. 



(Original from photograph.) . . ., . 



Within recent years, examples of the spe 

 cies which do this work have been 

 exceedingly scarce; consequently 

 but little evidence of its work can 

 now be found in the sapwood and 

 outer heartwood of living trees. 

 Therefore, there is no remedy for 

 the old work, and probably no 

 need of trying to combat an in- 

 sect which is apparently becoming 

 extinct. 



a Case Of this kind is to fell and B, sapwood; C, heartwood; a-6, brood cham- 

 ,.,. ,, i i ,, ber. (Adapted from author's illustration.) 



utilize to the best advantage the 



injured trees, and thus give the younger uninjured trees a better 



opportunity for rapid growth. 



The onlv thine- to do in FIG> 43 -- Brood * aller >' of Columbian timber- 



IU .> l beetle in sapwood of white oak: A, inner bark; 



