NOTES AND QUERIES. 25 1 



and as far as has been observed, they do not injure the 

 leading shoots which quickly grow through them. No further 

 operation is necessary. 



It has been found that oak takes three years to die after 

 being ringed. All the other species seem to die off in one 

 year, birch being the easiest killed of all. Mountain ash (or 

 rowan), where heavy, should perhaps be cut over before 

 planting, as it is inclined to be uprooted by wind a few years 

 after being ringed, and may cause damage to the young trees. 

 It is thought best, where possible, to do all the work on the 

 scrub during the first winter after planting. This gives the 

 young trees the benefit of the leaf canopy for two whole growing 

 seasons, by which time they are firmly established. In the 

 case of oak, of course, the ringing could be done at the same 

 time as the planting. Where it is impossible to undertake the 

 whole operation at once, it would at least be advisable to attend 

 to any part of the scrub which is so thick as to be likely to 

 prevent the growth of any vegetation beneath its shade, and 

 perhaps also to ring the oaks during the first winter after 

 planting. 



In this climate the Douglas fir and the silver firs seem able 

 to maintain a fair rate of growth under considerable shade, 

 but the spruces are not so accommodating. Sitka spruce, 

 especially, seems to be very intolerant of shade after three or 

 four years, and should receive attention before the others. 



H. L. Macdonald. 



Pine-root Aphis. 



Foresters and nurserymen are probably familiar with a white 

 woolly fluff found adhering to the roots of pine seedlings and 

 transplants, and may have noticed that where such fluff is 

 present the plants are often of poor colour and reduced vigour. 

 An examination of Scots pine transplants affected in this way, 

 which have been sent in from several nurseries during the past 

 two years, showed that the "fluff" was the woolly wax of an 

 aphis. Woolly aphids occurring on the roots of silver fir and 

 spruce have been described by various continental entomologists. 

 They belong to the family Pemphigidae which has affinities 



