F. V. TllKol'.AM) 



33 



Young excclsa do not present the same appearance as old ones when 

 attacked, the needles instead of turning brown arc mottled, where the 

 aphis sucks yellow spots appear and this lasts through the winter. 

 Writing from the Camolin Forestry Centre, Co. Wexford, Mr A. Stewart 

 sa3's " the aphis is extremely plentiful on young Sitka and Norway 

 spruce, but that in May not much damage had been done to the latter, 

 but the Sitkas are in many cases practically defoliated." 



Fig. 10 

 Sitka Spruce defoliated by Aphis abietina at Arndale (Dr Henry). 



Mr Murphy of the Kilrush Forestry Centre, Co. Clare, found the 

 few thousand Sitka spruce attacked, but not badly, but that both Sitkas 

 and Norway spruce in the plantations were practically immune. 



It thus seems that both the Norway and Sitka spruce are badly 

 attacked and then next comes pufigens, but that there is a marked 



Ann. Biol, i 3 



