PROCEEDINGS, 1915. 45 



pear, but also puncture the tender twigs. Later on they attack blossoms, 

 but when the fruit is set, they feed on it to the exclusion of other food. 

 The later stages will not feed on the leaves if other food can be obtained. 



Habits of Adults. 



Adult insects are, like their young, very active and take to 

 flight readily when disturbed. The nymphs prefer green pears to all 

 other food, but also feed upon the fruit of apples and plums. Pear- 

 trees kept free from the young insects by spraying had their crops de- 

 stroyed later by bugs flying in from nearby apple trees. 

 Character and Extent of Injury. 



1. Injury to the Apple. The first evidence of injury is to the 

 tender foliage in the form of purplish spots upon the surface of the 

 affected leaves, accompanied in severe cases by a slight tendency 

 to curl, as the leaves unfold and later reach full size, the discolora- 

 tion disappears, but if affected leaves are held to the light they 

 will be found to be pierced through and through with small holes. In 

 very severe cases they have a ragged, frayed appearance. 



The tender succulent twigs are favorite points of attack and as the 

 insect removes its beak a clear drop of liquid oozes through the bark. 

 Later, as the twig increases in size, quite a decided lump may develop at 

 the point of puncture, with, in severe cases, a cracking of the bark. In 

 heavily infested orchards where insects are present in hundreds of thous- 

 ands, the twigs may be literally stung to death, and afterwards remain 

 clinging to the tree for some time, in a brown dried-up condition. 



Blossoms are attacked with equal freedom and like them, may fre- 

 quently be stung to death by the countless number of beaks all with- 

 drawing their sap at the same time. The dead, dry blossoms usually fall 

 to the ground in a short time. These facts explain why susceptible vari- 

 eties bloom year after year without giving any crop. 



As soon as the young fruit has set, drops of gum oozing through the 

 skin, reveal the spot of the insect's attack. A slight reddish purple raised 

 spot will mark the puncture and the young apple generally drops, after 

 being stung. Fruit that is able to still cling to the tree, or that is not at- 

 tacked until it has reached some size, is usually badly gnarled and twisted 

 as a result of the insects' attack. The failure of the tissue about the punc- 

 ture to develop, results in a one-sided apple, with a pronounced depress- 

 ion, surrounding a brown slightly raised scar marking the spot where 

 the insect inserted its beak. 



Injury to Pears. Injury to the leaves, stems and blossoms of the 

 pear resembles that of apple, except that in this case the tissue about the 

 puncture turns black. Stinging of the young pears does not often result 

 in dropping as in the case of apples. The effect of the punctures on the 

 fruit is, however, very conspicuous, it being covered with hard, granular, 



