58 DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
ciously to the blossom clusters large numbers of them can be destroyed 
in this manner. This method of control, however, necessitates that 
they be collected daily for a period of two or three weeks or as long 
as they are at all numerous. Where large areas are to be covered, 
handpicking becomes expensive and involves a great deal of time, and 
Fic, 21.—Grape cluster from which berries injured by rose- 
chafer have fallen. (Original.) 
in addition to this many of the beetles are not removed from the vines 
until they have accomplished more or less injury. 
SPRAYING WITH ARSENICALS. 
Since the spraying of grapevines for other insect pests, such as the 
grape rootworm and the grape-berry moth, has been shown to be 
effective and has become a common practice, increased effort has been 
