446 Kepout of jiik JIokticultukist of the 



others suiter quite severely. With vurietiet; 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 seal) and other pear 

 diseases is given on page 452. 



PEAR INSECTS. 



BAKK LICE. 



See under " Oyster-shell liark-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 upc" 

 its soft tissues. Toward fall the adults migrate to the twigs to 

 remain all winter. There are probably several broods annuallv. 



Treaitnent. — The infested trees should be s]u-ayed 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. 



42 Beach. S. A. Bulletin 84 of this Station. 



