i8 99 .] 



ELM-BARK BEETLE 



171 



terning or tracks, but I do not see any reason at all to doubt 

 that this is attack of the very great elm-pest, the Elm-bark 

 beetle. With regard to its infestation of other trees besides 

 elm, I have no knowledge of its ever attacking either oak or 

 ash, but on careful search I find that one German writer 

 records it as "sometimes" attacking the ash. I greatly 

 doubt this having been observed in our country. Our 

 ashes have, however, a bark beetle which tunnels much 

 in the same manner between the bark and wood, and of 

 which the presence may similarly be known by the shot- 

 like holes in the bark. But you would distinguish the 

 difference in pattern of gallery at a glance on raising the 

 bark. As in the figure given, the mother - gallery is 

 branched. This Ash-bark beetle, Hylesinus fraxini, does 



Workings, showing forked "mother gallery," with larval galleries 

 from the sides. 



FIG. 36. TUNNELS OF THE ASH-BARK BEETLE, HYLESINUS FRAXINI, FAB. 



not do very much harm, for it chiefly attacks felled 

 trunks, or sometimes sickly or damaged trunks and boughs. 

 It is not to be compared in its ravages with the Scolytus, 

 well-named destructor. I am not aware of this ever attack- 

 ing oak. 



April 12, 1899. 



You have certainly two kinds of bark attack present in 

 the specimens which you send me, but without the beetles 

 I am not able to say at all what species may have been 

 doing the mischief. I can say quite certainly that I do not 

 see any signs of the presence of the Hylesinus fraxini 

 (Ash-bark beetle), but I have never, so far as I remember, 

 seen the very long, narrow borings, hardly wider than 



