46 N.S. ENTOMOLOGICAL SOCIETY. 



corky scars, which are often split open as in the case of those on the apple. 

 Hard, flinty areas extend into the pulp, making the fruit useless for any 

 purpose whatever. 



Injury to Plum. Injury to the fruit of plums is not uncommon, 

 where these trees border on affected apples or pears. Plums injured by 

 the bugs do not usually become scarred and twisted, as in the case of ap- 

 ples and pears, though they may sometimes grow somewhat one-sided. 

 The seat of injury is usually at the extremity of the fruit furthest from 

 the stem. As usual in the case of stone fruits this injury is marked by 

 the exudation of colorless gum which flows through the small puncture, 

 sometimes forming a globule and sometimes a coil of gum which finally 

 hardens in the air. 



Susceptibility of Varieties. 



Nonpareil (Roxbury Russet) is the most susceptible variety of ap- 

 ple, next in order comes Ribston, Gravensteins, Golden Russets, Blen- 

 heim, and Greening. There is a tendency in an orchard for the insect to 

 spread from the more susceptible to the less susceptible varieties. 



The Bartlett pear is more subject to attack than other varieties, but 

 Clapp's Favorite, Burbidge, Maria and Flemish Beauty are also affected. 



Conditions Favoring Increase. 



As a result of our observations throughout the infested area it ap- 

 pears that the most suitable conditions for an undue increase on the part 

 of the insect are shady orchards, with closely planted thick growing trees, 

 where air drainage is poor and a certain amount of herbage on the ground. 

 These conditions are not essential, however, as the pest is known to flour- 

 ish under all conceivable conditions. 



Control. 



Several factors make the control of this pest more difficult than that 

 of any insect with which we have to contend. First, the insect is very 

 active, and very clever at hiding, making it very difficult to hit it with 

 the spray. Second, when the tree is sprayed, large numbers of the young 

 insects drop to the ground and may reascend the tree when the spraying 

 is over. 1389 insects were found going up one tree after it had been spray- 

 ed — enough to ruin the entire crop. Third, the insects are capable of 

 coming to maturity on timothy, clover, couch grass, and other plants 

 that may be growing at the bottom of the tree, after which they can fly 

 back to the fruit trees and continue their work of destruction. 



The following are, therefore, the measures to be followed in control- 

 ling the Green Apple Bug: — 



