RA YAGERS OF CROPS 267 



which causes great injury both in the larval and 

 adult stage by boring galleries into and beneath 

 the bark, and sometimes by slightly cutting into 

 the outside wood of the tree. The principal 

 damage, however, is caused by the bark being 

 loosened and the regular circulation of the sap 

 thereby arrested, and by rain soaking in through 

 the innumerable small holes bored in the bark 

 by the young beetles in making their escape, 

 after passing through their metamorphosis under 

 the bark ; indeed, after their emergence the bark 

 of an ash tree frequently presents the appearance 

 of having been riddled with shot. 



The elm also suffers from the depredations 

 of a bark-burrowing beetle, which bores its 

 galleries between the bark and the wood, but 

 chiefly in the soft inner bark. The tunnels of 

 these beetles present rather a remarkable ap- 

 pearance, showing a large central gallery with 

 numerous smaller galleries opening, and all 

 going off, at right angles from it. The main 

 gallery, which is generally about three to five 

 inches long, is the work of the female beetle, 

 and its excavation takes her about three weeks 

 to complete. In this central burrow she deposits 

 her eggs at regular intervals, and along each 

 side, to the number of one hundred to one 

 hundred and sixty. Directly the larvae emerge 

 from the eggs they start at right angles from 

 the main gallery, and proceed to gnaw their way 

 onwards through the bark, their burrows in- 

 creasing in size as the larvae increase in bulk. 

 When full grown, they change to pupae within 

 the galleries they have formed, and many remain 



