10 ASH. [1900 



H. fraxini, Pabr., is by far the most common of onr four British 

 species. It is from two and a half to three and half millimetres in 

 length — that is, from somewhat over a twelfth to somewhat over an 

 eighth of an inch in length — short and convex ; on the upper side 

 pitchy, reddish, or dusky in colour, rarier/ated with ashy and fuscous scales; 

 beneath with an ashy down ; antennae rusty, with the club larger. 

 Thorax transverse, finely and granulately sculptured wing-cases with 

 fine punctured strife, interstices broad, rugosely sculptured ; legs 

 black ; feet red or rusty. 



The figures of 71. crenatus at the heading of the following paper 

 give a very fair idea of the shape of H. fraxini, much magnified ; but 

 from this species H. fraxini is distinguished by H. crenatus being 

 noticeably lar(/i>r — this is as much as 4-5 millimetres in length — and 

 also it is usually deep black in colour and shiny (not with a pattern on 

 the beetles of dusky or lightish scales, as is the case with H. fraxini). 

 From H. olcipcrda (which is of the same length as H. fraxini) this may 

 be clearly distinguished by H. oleiperda having usually " a band of 

 whitish grey hairs along the suture " (W. W. F.) — that is, along the 

 central line of meeting of the wing-cases ; and H. vittatus, the smallest 

 of our four British Hi/lesini, which is from 1^-2 millimetres long, is 

 thus easily distinguished from H. fraxini. 



Although H. fraxini is so common and so widely distributed, I have 

 rarely had enquiries sent me regarding the attack ; but in the spring 

 of the year 1875, the beetles appeared in such great numbers on the 

 trunks of some newly felled Ash trees at Osterley Park, in the 

 neighbourhood of Isleworth, as to afford me an opportunity of 

 watching the commencement of their boring operations, of which 

 I give some notes from the account by myself in the 'Entomologist,' 

 vol. X. pp. 183-187. 



In this case the trees had grown to the average height, and were 

 about a foot in diameter ; they had grown (and the felled trunks were 

 laid) in a damp locality, and the part chiefly attacked was the lower 

 side of trunks next the grass. 



The work was begun about April 19lh, the beetles being then 

 wandering in great numbers over the timber until an appropriate spot 

 being found, and the boring commenced, the beetles continued steadily 

 at their work, irrespective of any disturbance ; the smooth surface of 

 the bark, or any of the slight fissures, appeared to be selected indiffer- 

 ently by the beetles as the commencement point of their burrows. 



In four dai/s the Hi/lesini had disappeared, the only signs of their 

 presence being the thrown-out matter from their borings, then in 

 progress, inside the bark. The progress was very slow ; in captivity 

 the beetle made an advance of only half its own length in from ten to 

 twelve hours, and in natural circumstances of rarely more than half 



