Some Insects of the Apple and Their Control 1743 



every year. This is especially true in localities where little 

 attention is given to fruit-growing. In this lies a hint that thor- 

 ough spraying and cultivation of orchards each year as practiced 

 by our most successful growers are, perhaps, the most satisfactory 

 means of avoiding injury by this pest. The only remedy that 

 experience has shown to be effective in reducing the injury on 

 badly-infested varieties is the destruction of windfalls, which is 

 ordinarily accomplished by pasturing the orchard with hogs or 

 sheep. Recently the use of poisoned bait has been recommended 

 for the destruction of the fly. The method employed is to syringe 

 the lower branches with a mixture of molasses one pint, arsenate 

 of lead three ounces and water four gallons. 



Insects that Attack the Foliage 



THE BLISTER :MITE 



This has in recent years become an important pest of the apple. 

 Its work is now quite common in plantings that are neglected or 

 indifferently sprayed throughout the apple-growing sections of 

 western Xew York. Destructive outbreaks of the pest have also 

 been noted in orchards about Lake Champlain. 



Fig. 139. The Blister Mite (miicli enlarged) 



The mite that is responsible for the injury to the foliage is a 

 microscopical, vermiform creature as shown in fig. 139. The mites 

 burrow into the leaves from below and the irritation they cause 

 induces the growth of galls. These at first are greenish pimples 

 with a more or less reddish tinge. The color strengthens as the 

 galls increase in size, appearing as dead, corky areas of varying 

 size. These galls or l)]isters on apple foliage resemble, in general 

 effect, the spots produced by bordeaux when sprayed under unfavor- 

 able weather conditions, but the bordeaux spots are depressed or, 

 at least, are not raised above the surface of the leaf, while the 



