1900] 



ASH. 



Common Ash-bark Beetle. Hylesimis fraxini, Fabr. 



Workings of Hylesinus fraxini, showing forked " mother-galleries 

 galleries from the sides. 



with larval 



The Hylesinus fraxini, popularly known as the Common Ash-bark 

 Beetle, does mischief by means of its white footless fleshy grubs which 

 work in the bark of Ash trees {Fraxinns excelsior), and though they 

 appear to have an especial preference for newly felled timber, yet the 

 infestation is also to be found in decayed or sickly trees, and sometimes 

 in young trees. In these the attack is certainly mischievous by reason 

 of the galleries stopping the full flow of the sap ; and though in felled 

 trunks the damage is little or none, they act as regular nurseries for 

 recurrence of attack. As the signs of the working in the bark are 

 very noticeable during a part of its progress by the quantity of wood 

 dust thrown out by the beetles at the commencement of their burrow- 

 ing operations, preventive measures may be applied at once with little 

 trouble or cost. 



Tlie above figure shows the very short central entrance-gallery 

 through the bark branching to right and left into two galleries, usually 

 of about even length. These are formed by the pair of parent beetles, 

 the male and female ; and along the sides of tbese tunnels, or galleries, 

 the female lays her eggs, each in a little hollow dug out to receive it. 

 These are laid at about even distances from each other, and are 

 recorded as being covered with a kind of gummy material ; also that 

 the gallery is finished and the eggs laid in it in from ten to twenty 

 days, after which both of the beetles usually die in the burrow, and 

 the female is stated always to do so.* 



* For observations on the habits and transformations of Hylesinus crenatus, 

 H. fraxini, and H. vittatus, see paper by T. Algernon Chapman, M.D., in Ent. Mo. 

 Mag. vol. V. pp. 120-123 ; also for specific descriptions of the above and H. oleiperda, 

 see ' Coleoptera of the British Islands,' by the Eev. Canon Fowler, vol. v. pp. 417-419. 



