DESTRUCTIVE ANIMALS, BIRDS, INSECTS 123 



take measures against it. The young insects are within the 

 gall when it is soft and green, and galls in this stage on 

 nursery plants and young transplants might be cut off with 

 a pair of scissors and burnt It is useless to remove old galls 

 as these are empty. 



Fig. 7. Gall of Chermes 

 abietis, L., on a spruce-twig. 

 (Natural size.} 



Fig. 8. Larch-shoot attacked 

 by Chermes laricis, Hart. (Natural 

 size.) a Insects feeding on the 

 needles, which show a charac- 

 teristic angular bend. 



The Larch aphis (Che fines laricis). 



This aphis sits and feeds on the needles of larch. The 

 needle is bent over at the spot where the aphis is feeding. 

 At first it looks like a black spot on the needle, but after- 

 wards becomes covered with a woolly down, and, if numerous, 

 the larch look as if sprinkled with snow. When numerous the 

 health of the trees suffers, and, moreover, they are probably 

 more apt to be attacked by the larch canker, the spores of the 



