SYLVICULTURAL NOTES ON SILVER FIR. 289 



A weevil, Pissodes picece, peculiar to this species, is 

 destructive chiefly to sickly trees. The wood-wasps 

 (Sirex) and some Tomicidoe bore into the wood, especially 

 when newly felled. 



Mistletoe is frequently found ton Silver Fir, perforating 

 the wood and reducing its value. 



Of Fungi, ^Ecidium elatinum, Lk., must be mentioned, 

 which causes witches' broom and cancer on the Silver 

 Fir; this evil occurs sometimes on a large scale. To 

 meet it the diseased stems should be cut out as soon as 

 possible. Of other fungi, Phytophthora omnivora, Pesta- 

 lozzia Hartigii, Agaricus melleus and Trametes radiciperda 

 may be mentioned, but they do less damage than in the 

 case of Spruce. 



The Silver Fir stands pruning well. 



Young Silver Fir woods should be carefully watched, 

 especially if mixed with other species, lest the slow- 

 growing Silver Fir may be outgrown and injured. 



Thinnings need rarely commence before the 25th or 

 30th year ; they should be light until the woods enter 

 the last third of their life, when they should be heavy, 

 so as to cause the remaining trees to increase rapidly 

 in diameter. Throughout the thinnings all trees infected 

 with cancer should be removed, unless by so doing the 

 wood might become too open ; in some cases it may be 

 possible to remove the witches' broom before the stem 

 has become infected. 



VOL. II. 



