New York Agricultural Experiment Station. 361 



not kill the trees or branches as the blight may do, still it is beUeved 

 that no disease, year after year, causes so great loss in pear orchards 

 of New York State as does the scab. Some varieties appear to be 

 comparatively exempt from its attacks, while others suffer quite 

 severely. With varieties which are thus injured by the 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 number one 

 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. 



Remedy. — The treatment of this disease is discussed quite fully 

 in Bulletin 8-1 of this Station. It is the same as that recommended 

 for apple scab. See p. 346. 



Bltd Moth. — This eye-spotted bud moth, which attacks pears is 

 the same as that which infests apple trees. It is also known as the 

 bud worm. Treatment for it is given under apples. See p. 347. 



Case Bearer. — This insect also infests apple trees and has been 

 considered under apples. See p. 349. 



Codling Moth. — This insect, which causes so much loss to apple 

 growers by causing wormy apples, also attacks pears. It may be 

 treated in treating scab as recommended under apples. See p. 350. 



PsYLLA. — This is the name given to an insect which injures the 

 tree by sucking its nourishment from the leaves. The insect when 

 mature is nearly a tenth of an inch long, the full grown wingless 

 form being about half as long. Its presence is usually betrayed by 

 the honey dew which is secreted by the young wingless forms of 

 the insect. The honey dew afterwards becomes covered with a 

 b ack mold giving the leaves, fruit, or branches on which it is found 

 a black, unsightly appearance. The following statements and 

 recommendations for treatment are based chiefly on Slingerland's 

 account*' published in 1892. 



The adult is an active, four winged insect, resembling in minia 

 ture a seventeen year locust or cicada. A number of broods of the 

 psylla are produced during the summer, and the adults which live 

 through the winter are distinct in form from the summer adults. 

 They appear early in the spring and deposit their eggs which hatch 

 in a few days and the little larvie or nymphs at once commence to 



Bulletin 44 ; Coiuell Exp't Station, Ithaca, N. Y, 



