ENEMIES OF CONIFEROUS TREES 271 



a parasite on the living foliage. We have been 

 most successful in combating the attacks and 

 preventing the spread of the pest by spraying 

 the affected parts with '' Bordeaux mixture/' 

 Young trees under ten years of age are most com- 

 monly attacked, and when this occurs in the 

 nursery borders, the plants should be rooted out 

 and burned. On several Scottish and English 

 estates thousands of Scotch Pines have been 

 killed by the attacks of the leaf -shedding fungus. 



Pine Cluster-cups {Peridermmm pinicicola), — 

 Next to the Larch Canker, one of the most de- 

 structive diseases of forest trees is caused by 

 attacks of the Bladder-rust or Cluster-cups. It 

 is a wound fungus and attacks almost every species 

 of pine, the Scotch in particular, and especially 

 when the trees are growing on light, poor soils. 

 Young trees up to, say, twenty years old, are most 

 commonly attacked by this fungus, which appears 

 like blisters, emitting bright reddish-coloured 

 spores. Rooting up and burning all affected 

 trees is the best remedy. 



Sclerotinia. — In the life-history of this fungus 

 there are several distinct stages, that known as 

 Botrytis being by far the most injurious to trees, 

 and causing the now well-known and much- 

 dreaded leaf-shedding of certain coniferous trees. 



Young trees whilst in the seed-bed or nursery 

 stage of growth are most commonly attacked, 

 though instances are on record of the foliage on 

 tender shoots of old trees being damaged by this 

 parasitic fungus. Few of the commonly cultivated 

 coniferous trees would appear to come amiss to 

 the attacks of the Botrytis, the Larch, owing no 



