78 EXPERIMENTAL FARMS 



6-7 EDWARD VII., A. 1907 



work has been done in preventing the spread of this scale insect, by a minute chalcid 

 parasite, Aphelinus mytUaspidis, Le Baron. It is bright yellow in colour with golden 

 eyes and measures only aboiit one thirty-sixth of an ijich in length ; being so small it 

 can hardly be seen with the naked eye. The parasite is sometimes so abundant that it 

 destroys more than half of the scales that are formed. Its presence on an infested tree 

 can be detected by the small round holes made through the scales when the flies emerge. 



Remedies. — Although so destructive in aU parts of Canada, the Oyster-shell Scale 

 k not a particularly hard insect to control, where trees are attended to regularly. 

 The first step to take when an orchard is found to be attacked is to invigorate the trees 

 by ploughing round them and feeding them with some quick-acting fertilizer, such as 

 well-rotted manure, or a dresing of wood ashes. When trees have been standing in sod. 

 it is well to breal<; this up. Trees which are planted too closely, should be pruned and 

 cleaned out, so that they may be easy of access for spraying and other operations. As 

 soon as winter has set in, the trees should be sprayed thoroughly with a thin lime wash, 

 one pound of lime in each gallon of water. Two coats must be applied, the second im- 

 mediately after the first is dry. Where the lime-sulphur-and-salt wash is used to protect 

 trees against fungous and insect enemies, there will never be any trouble with the Oyster- 

 shell Scale. The young bark-lice emerge from their mothers' scales about June; 

 the exact date should be watched for, and. immediately the dust-like yellow mites are 

 noticed, the trees should be sprayed without delay with weak kerosene emulsion, or a 

 whale-oil soap solution, using one pound to six gallons of water, 



Pear-Leaf Blister Mite {Phytoptus pyri, Nalepa). — A considerable amount of in- 

 jury is done every year in all parts of Canada, where the pear is grown, by the opera- 

 tions of the Pear-leaf Blister-mite: The irregular blotches about one-eighth of an inch 

 in diameter and frequently confluent, caused by these mites are frequently so abundant 

 on the foliage as to make it impossible for the leaves to perform their functions. These 

 blotches when examined are found to he hollow blister-like galls with a hole in the 

 centre through which large numbers of almost invisibly small mites issue and attack 

 fresh parts of the leaf. Few people recognize this injury as the work of an insect at first' 

 sight. It is nearly always sent in as a fungous disease, but if one of these galls is cut- 

 open and examined with a strong magnifying glass it is easy to detect the white elong- 

 ated mites with which tl?c inside is filled. The remedy for this insect enemy is to spray 

 the trees just before the leaf-buds expand with the lime and sulphur wash. The sul- 

 phur is practically obnoxious to all kinds of mites, and it has been found that this 

 gerious enemy of the pear-grower may be practically exterminated with a single 

 thorough spraying with the mixture above mentioned. 



Cakkerworms. — Slender brown or green loopers, or * measuring worms,' about an 

 inch in length when full grown, and with only six pairs of legs, three pairs of which are 

 on the front part of the body and the others close to the other end, causing the cater- 

 pillars when they walk to raise the central portion into a loop. These are the caterpillars 

 of two kinds of geometrid moths which lay their eggs on the trees in the autumn in one 

 species, and in the spring in the other. The injury done by these caterpillars is some- 

 times serious and where neglected they increase so much in infested orchards that 

 sometimes the greater part of the foliage may be destroyed before they are noticed. 



The remedy is to spray the trees as soon as the young caterpillars appear. After 

 they have become half grown they require much stronger poisons to kill them than 

 many other insects. When they have been neglected it is perhaps better to use arsenate 

 of lead than Paris green and as much as a pound of the poison may be used to 50 

 gallons of water or Bordeaux mixture. As the females are wingless and crawl up from 

 the ground to deposit their eggs on the trees, many may be prevented from egg-laying 

 by mechanical contrivances or they may be caught on bands of thick paper painted 

 with a mixture of castor oil, two pounds and resin, three pounds, for cold weather, but 

 in hot weather it is necessary to add one more pound of resin. These are heated slowly 

 until the resin is all melted and the mixture is applied to the bands while it is warm. 



