ASH-BARK BEETLES 



173 



with a short stem and long arms to the top, and the larval 

 galleries placed at right angles to the others (fig. 36), so 

 far as I understand this form is not followed by crenatus 



(fig. 38). 



The beetle obviously pierces the bark, for the orifice is 

 visible ; and in or under the bark there are the mother- 

 galleries, but I do not find the larval galleries feathering as 

 it were from these, and the figure before me gives the idea 

 of the body of larvae having by their united attack cleared 

 a flat space from which they have continued their solitary 

 tunnels. Perhaps in cutting up your trees you may come 



FIG. 38. PIECE OF ASH BARK, SHOWING MOTHER GALLERIES OF 

 HYLESINUS CRENATUS ON THE INNER SIDE. 



on some of these markings. It is said that there are two 

 generations in the year, of which the flight time of one is in 

 April and of the other in October. This species frequents 

 oak as well as ash, which is an important consideration, 

 and I find it noted as frequenting old trees. These are the 

 main points which I see about the history. I should think 

 that if you find the trees which you have felled much in- 

 fested, it would be a good thing to strip the bark off 

 and burn it. 



June 25, 1900. 



I am very much obliged to you for all the great 

 trouble which you have been good enough to take about 



