The Pine Beetle (Hylurgus piniperda). 



By THOMAS WILKIE, Forester, Ardkinglas, Cairxdow, Argyleshire. 



It is believed by some that this beetle is only propagated by conta- 

 gion, or by allowing the branches of felled trees to lie and rot upon 

 the ground. But recently, in passing through a young plantation 

 formed upon fresh soil formerly cultivated, a mile distant from any 

 other plantation whatever, and in which no cutting or thinning had 

 ever taken place, I observ^ed it was working great destruction upon the 

 Scotch and Austrian pines. On inquiry I found it had never been 

 observed till this season, although the plantation had been formed for 

 ten years. This naturally shook my belief in the theory above 

 mentioned, and when asked by the forester in charge what was my 

 opinion of the case, I could give no other than that their propagation 

 is due entirely to a counteraction of the sap, by its being retarded in 

 its ascent or descent by uncongenial weather, sach as a cold spring or 

 possibly frosts. 



Perhaps some observant person may give us some light upon this 

 subject, for I have never yet heard any idea expressed other than that 

 enumerated above, and some writers have advanced statements which 

 would attribute their propagation to wasting of the branches of 

 the thinnings as the only cause. I have no doubt whatever that they 

 soon increase to an enormous extent when once settled in a plantation, 

 but this may be due almost exclusively to their fecundity. But how, 

 or by what means, were they first brought into it ? Would it be, or is 

 it possible, that they make shiftings or removals from one place to 

 another ? 



As the best means to reduce their numbers, I would suggest that 

 periodical examinations be made of all our young plantations, and with 

 an averruncator, or pocket knife, cut off the twigs in which they are 

 and carefully gather them into a leathern apron, or some such article, 

 and burn them on the nearest spot of safety. Such expense would be 

 comparatively small, as two careful boys would manage the whole 

 operation. 



For my own part I have never yet seen this insect upon],the wasting 

 branches on the ground, although I have often seen another one 



