270 



THE CANADIAN HORTICULTURIST 



Floral Edition. 



Injured apples. 



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 in- 

 sects by spraying had their crop de- 

 stroyed later by bugs flying in from 

 nearby apple trees. 



The first evidence of injury to the 

 apple is to the tender foliage in the 

 form of purplish spots upon the sur- 

 face of the affected leaves, accompanied 

 in severe cases by a slight tendency to 

 curl. As the leaves unfold and later 

 reach full size, the discoloration disap- 

 pears, 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 fav- 

 orite 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 punc- 

 ture, with, in severe cases, a cracking 

 of the bark. In heavily infested or- 

 chards where insects are present in 

 hundreds of thousands, the twigs may 

 be literally stung to death, and after- 

 wards remain clinging to the tree fo? 

 some time, in a brown, dried up condi- 

 tion. 



Blossoms are attacked with equal 

 freedom, and like them may frequently 

 be stung to death by the countless num- 

 bers of beaks, all withdrawing their 

 sap at the same time. The dead, dry 

 blo.ssoms usuallv fall to the ground in 

 a short time. These facts explain why 

 susceptible varieties 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 will mark the 

 puncture and the j'oung apple gener- 

 ally drops after being stung. Fruit 

 that is able to still cling to the tree, or 

 that is not attacked until it has reached 

 some size, is usually badly gnarled and 

 twisted as a result of the insects' at- 

 tack. The failure of the tissue about 

 the puncture to develop results in a 

 one sided apple, with a pronounced de- 

 pression, surrounding a brown, slightly 

 raised scar, marking the spot where 

 the insect inserted its beak. 



Injury to Pears. 



Injury to the leaves, stems and blos- 

 soms of the pear resembles that of 

 apple, except that in this case the tissue 

 about the puncture turns black. Sting- 

 ing 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, 

 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 pur- 

 pose whatever. 



Injury to Plums. 



Injury to the fruit of plums is not 

 uncommon, where these trees border 

 on affected apples or pears. Plums in- 

 jured by the bugs do not usually be- 

 come scarred and twisted, as in the 

 case of apples 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 ex- 

 udation 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 apple, next 

 in order coming Ribstons, Gravensteins, 

 Golden Russets, Blenheim and Green- 

 ing. There is a tendency in an orchard 

 for the insect to spread from the moi'e 

 susceptible to the less susceptible varie- 

 ties. 



The Bartlett pear is more subject to 

 attack than. other varieties, but Clapp's 

 Favorite, Burbridge, Maria and Flem- 

 ish Beauty are also affected. 



Conditions Favoring Increase. 



As a result of our observations 

 throughout the infested area it appears 

 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 con- 

 ditions are not essential, however, as 



the pest is known to flourish under al! 

 conceivable conditions. 



Several factors make the control of 

 this pest more difficult than that of any 

 insect with which we have to conicnd. 

 First, the insect is active, and clever 

 at hiding, making it 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 re- 

 ascend the tree when the spraying is 

 over. On one tree 1,389 insects were 

 found going up it after it had been 

 sprayed — 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. 



Methods of Control. 



The following are therefore the mea- 

 sures to be followed in controlling the 

 Green Apple Bug: 



First: In normally planted, well 

 pruned orchards, with only a moderate 

 infestation, spraying the apples with 

 Blackleaf 40, one pint to 100 gals., just 

 before and just after the blossoms fall, 

 and pears just after the blossoms fail 

 and again five days later, should be 

 sufficient. In others special measures 

 must be taken. 



Second: The trees must be banded 

 with tree tanglefoot to prevent the re- 

 ascent of those insects that have fallen 

 to the ground. 



Third : The orchard must be kept in 

 a state of clean cultivation until the 

 end of the first week in July, in orde." 

 to starve all insects that have been 

 forced down the tree. 



Fourth : The trees must be thor- 

 oughly thinned out and pruned, so that 

 all parts can be reached by the spray. 



Fifth: A heavy drenching spray 

 must be given. 



I believe in the future of the 

 Nova Scotia apple industry. Wc 

 are in a strategic situation 

 here for catering to the British 

 market, and so far as I can see our posi- 

 tion in the future will grow more and 

 more secure. The major portion of the 

 production of - Ontario and British 

 Columbia will in time be taken care of 

 by the' growing populations of our 

 prairie provinces and of our rapidly- 

 expanding inland cities. We shall be 

 able to do something in those directions, 

 too, but our principal market will al- 

 ways lie across the Atlantic. Dealers 

 and consumers over there are becoming 

 more widely acquainted with our pro- 

 duct every year, and the greater the 

 spread of this knowledge the strongT 

 the demand.— W. W. Pineo, Water- 

 ville, N.S. 



