64 RATIONAL FRUIT CULTURE, 



made by wasps and birds. Another serious charge has 

 been brought against them — that they tend aphides during 

 the winter, and carry them from place to place. As they are 

 very fond of the sticky fluid secreted by the aphides, it is 

 possible. Certainly, they usually abound where the latter are 

 numerous, and they are not likely to cause trouble if the 

 aphides are cleared away. Syrup, containing arsenic, is some- 

 times recommended for poisoning them, but anything of this 

 sort is very dangerous in a garden. The only really effective 

 way of getting rid of wasps is to search for and destroy the 

 nests. 



INSECTS THAT l.\,ll KE THE SHOOTS. 



The chief insects which damage the wood of fruit trees 

 are the mussel scale (previously dealt with in connection with 



Fig. 22.— Woolly Aphis or American Blight, highly magnlRed 



foliage), the oyster-bark scale, and the woolly aphis. There 

 are several others which bore into the wood, but they are not 

 very common, except, perhaps, in old and neglected orchards. 



Oyster- Bark Scale. — Apple, Vcm. Plum, Cherry. 

 lioiinder in shape than the usual mussel scale, but verv 

 .similar in its habits. Paraffin emulsion while the iree.s are 

 in leaf; in winler, Woburn wash. 



Woolly Aphis, — Apple, sonietimeH Pear. These insects 



