50 



stimulated the trees to renewed growth, that it improved 

 their general condition, and that the new bark which re- 

 places that which is removed is so smooth and thin that 

 the beetles will not resort to it to deposit their eggs. .The 

 treatment, it is held, does no injury to the trees. M. 

 Robert treated at one time over 2,000 ti-ees along the 

 boulevards and public roads of France with marked. suc- 

 cess. The same treatment serves, it is said, to invigorate 

 apple trees which have ceased to bear, and has long been 

 employed by fruit growers in Normandy. 



Pine Bark-Beetles. 



(Tomicus calligraphus, etc) . 



Pine trees in cultivation sometimes suffer from the 

 minings of small stout bodied grubs which destroy the 

 inner bark in much the same manner as the elm borer . 

 Several different species of the same family (Scolytidse) 

 are often concerned in this work of destruction, but the 

 one found abundantly on pines in this vicinity is the spe- 

 cies named above. 



The adult beetle is a small compact, cylindrical, brown 

 object about 0.20 inch long, with short legs, and is to be 

 known from beetles of other kinds by a singular excava- 

 tion at the extremity of its body with" toothed edges. It 

 looks as if it had been mutilated by having the hind part 

 of the wing covers gouged out. These beetles bore into 

 the bark of trees making a channel of some length which 

 after the inner bark is reached, is made parallel with the 

 surface. The eggs are placed at intervals along this 

 channel, and the grubs hatching from these push into 

 the adjacent bark, so that it becomes eventually com- 

 pletely destroyed by them. 



The adults appear very early in the spring, being ob- 

 served by us to be abundant under the bark of an Aus- 

 trian pine at Lexington, February 29. At this date no 



