PAKT II. 



FOREST TREES 



INSECTS THAT INJURE THEM. 



ASH. 



Ash-bark Beetle. HyUsinus fraxmi, Fab. 



Workings of Hylesinus fraxini, showing forked "mother gallery," with larval 

 galleries from the sides. 



The Hylesinus fraxini is injurious, both in the beetle and 

 grub state, to Ash trees, by boring galleries beneath the bark, 

 sometimes slightly cutting into the outside wood of the tree. 

 The beetles are often attracted in large numbers by newly- 

 felled Ash trunks, in the bark of which they propagate, and 

 from whence the new brood spreads to the neighbouring trees, 

 mainly attacking those that are sickly or decayed ; or young 

 trees, which they sometimes injure to a serious extent. The 

 damage is caused not only by the bark being loosened and the 

 regular circulation of the sap interfered with, but also by the 

 multitude of small holes which the beetles bore in escaping 



