APHIDID^E. 335 



the latter, as remarked, on young trees. As regards remedies for 

 G. abietis in the nursery, this is a very good case in point where 

 good husbandry is advantageous both to the seller and purchaser. A 

 general saleable age of the spruce plants is five years namely, two 

 years in the seed-bed and three years in the rows, 2 yrs. 3 yrs. of 

 the nurseryman. When transplanting from the seed -bed they are, 

 of course, placed very thickly in the rows, and if they do well, are 

 useful stulf as 2 yrs. 2 yrs., but when unsold the nurseryman must 

 either leave the crop as it is or otherwise compromise matters by 

 interlining. .The latter method does not give relief between plants, 

 and the consequence is that they are afterwards weakly much to the 

 advantage of the Chermes. Again, three years in the nursery-line is 

 conducive to bad roots, which, coupled with the depreciation from the 

 insect attack, means a very poor class of plant to the purchaser. 



Hence, in order to maintain health and vigour, the practical remedy 

 is, at the end of two years, transplant again for another two years 

 provided, of course, the seller could secure purchasers who recognise 

 that quality and not cheapness is the essential of success. By doing 

 so on suitable soil, we should get a better plant, and thus lessen 

 the attack of the Chermes. This could always be done on private 

 estates. 



Another point in connection with the planting of spruce in the 

 young woods associated with Chermes may be mentioned viz., that 

 in some parts of the country the spruce should not be planted in the 

 open amongst the more hardy species, but used more as an after-plant 

 for filling up. In the latter case it will thrive better, and though 

 attacked by 0. abietis, does not suffer to any appreciable extent, 

 inasmuch as on vigorous plants the galls are often considerably on 

 one side of the shoot, and thus the subsequent growth overcomes 

 the attack. 



Another point in connection with Chermes and practical forestry 

 may be mentioned viz., that it has been asserted by some observers 

 that the mother Chermes on larch inoculates 1 the tree with the spores 

 of Peziza, which is the fungus causing the well-known " larch disease." 

 Hence it would obviously appear that a mixture of spruce and larch 

 would favour the insect, and consequently be conducive to the spread 



1 It is just possible that the wounds caused by the insects form suitable spore- 

 beds, just as apple canker will develop in the wouuds of S. lanigera, and can only 

 do so in wounds. 



