446 Report oF THE HorricuLTuRIST OF THE 
others suffer quite severely. With varieties which are thus in- 
jured by its attacks, it weakens the tree, it lessens the yield, it: 
makes a large part of the fruit unsalable or of an inferior grade, 
and even the No. 1 fruit sells for less in the market than it would 
were it free from the blemishes caused by the scab. It is also 
conceded that fruit free from scab keeps better and is handled 
easier than the fruit of the same variety blemished with scab spots. 
Treatment.— This disease may be controlled by treatment with 
Bordeaux mixture.*# Paris green or its equivalent may be used 
at the same time against the codling moth and leaf eating insects. 
The general treatment recommended for the scab and other pear 
diseases is given on page 452. 
PEAR INSECTS. 
BARK LICE. 
See under “ Oyster-shell Bark-louse” and “ Scurfy Bark-louse.” 
BLISTER MITE. 
(Phytoptus pyri Scheuten. ) 
Description.—The first indications of the presence of this insect 
in the spring are the small reddish spots on the upper surfaces of 
the young leaves. These spots indicate where the adult mites that 
have been hibernating on the twigs burrowed into the leaves to 
deposit their eggs. These spots finally turn black. The eggs 
soon hatch and the young mites burrow into the leaf, feeding upon 
its soft tissues. ‘Toward fall the adults migrate to the twigs to 
remain all winter. There are probably several broods annually. 
T'vreatment.—The infested trees should be sprayed in the spring 
a short time before the buds burst, either with kerosene emulsion 
diluted with seven parts of water or with a solution of whale-oil 
soap, one pound to seven gallons of water. One thorough appli- 
cation has been found to be sufficient. Pruning closely in winter 
and burning the twigs will also aid in checking the insect. 
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42 Beach, 8S. A. Bulletin 84 of this Station. Hes | 
