272 



FAMILY CERAMBYCIDAE 



they may entirely remove all the bast, on which they feed, round a 

 section, or even in course of time from the whole of the stem of a 

 tree, which thus becomes completely girdled and dies. When such an 

 attack is in progress, if the outer dead bark be removed a mass of 



wood, sawdust, 

 and larval excreta 

 will be found 

 blocking these 

 galleries, consist- 

 ing of the undi- 

 gested residue of 

 the bast and sap- 

 wood consumed 

 by the grub, 

 which it ejects, 

 and leaves block- 

 ing its gallery 

 behind it as it 

 tunnels onwards 

 in the tree. When 

 such a mass is 

 found beneath 

 the bark of a 

 dying or dead 

 tree it forms an 

 evidence of the 

 former and pre- 

 sent presence of 

 longicorn beetles 

 in the tree. Ex- 

 ternally the tree 

 itself shows by 

 its sickly appear- 

 ance and the 

 falling of its 

 needles or leaves 

 that it is suffering 

 from some attack 

 which is killing 

 it. Noteworth\' 

 examples of such 

 attacks actually 

 observed and reported, although the aggressor was still unknown, were 

 the great longicorn {.^olesthcs sarta) attack which decimated the poplar 

 and willow avenues on the roads in Quetta, reported in 1904 by Col. A. 



Pig. 188. — Section of a stem showing large flat galleries eaten out 

 in the sapwood by cerambycid gru1)s and the entrance-holes to the 

 pupating-chamliers in the wood. 



