REPORT OF THE ENTOMOLOGIST AXD BOTANIST. 231 



SESSIONAL PAPER No. 16 



greatest degree on cherry trees, and aphids were quite destroyed. Even when trees 

 were in blossom, no injury from the soap was noticed. The treating of trees with the 

 whale-oil soap did not prevent the young scales from settling soon afterwards on the 

 parts treated. 



Crude petroleum gave better results as far as the scale was concerned. A mechani- 

 cal mixture of water with 30 per cent crude petroleum could be used quite safely 

 on apple trees, and also with care upon plum and peach trees ; even this, however, 

 was not a perfect remedy, as all the trees treated had some scale upon thera at 

 the end of the season. Mr. Fisher considered that a combination of whale-oil soap 

 and crude petroleum would probably be found the best remedy. He did not think it 

 safe to recommend crude petroleum for general use. The ordinary fruit grower 

 would not use even the whale-oil soap in accordance with instructions, and he felt 

 sure they would use crude petroleum in the same careless way, and trees would be 

 killed. He believes that a frequent cause of injury from crude petroleum when 

 applied with water is that operators when spraying, go over trunks and other parts 

 of trees twice ; beginning on the trunk, they go over the tree and finish up again, on 

 the trunk, thus depositing two applications or twice the necessary quantity of oil,, 

 because the water evaporates quickly but leaves the oil on the tree. Imperfect work 

 is frequently done from the difficulty of reaching the upper side of the high branches 

 on the opposite side of a tree which is being sprayed. The best time to apply the 

 spray, whether of soap or of crude oil, is in April. 



A word of warning may be here inserted for the benefit of those who may wish 

 to use crude petroleum with regard to the variation in the specific gravity of crude 

 petroleum from difierent wells. Dr. J. B. Smith, who has certainly done more to test 

 the value of this remedy than anyone else, says (New Jersey Bulletin, 146), after 

 giving the specific gravity of several samples : — 



' Thus thirteen samples register 50° or over, leaving 70 that run between 40^ 

 and 49°, the majority running nearer to 46° than to 44°, both in green and in amber 

 oils. It is a fair requirement, then, for a straight crude petroleum that it should have 

 a specific gravity of 43° or over, at a temperature of 60° Fahr. ; anything less 

 might be harmful; anything more than 45° is unnecessary. 



The importance is thus shown of knowing what the specific gravity by the 

 Baume oil scale is before any sample is used by a fruit-grower upon his trees. 



The San Jose Scale exists in Canada only over a small area of the province of 

 Ontario, extending from Niagara around the western end of Lake Ontario as far 

 as Burlington and westward through the counties bordering on Lake Erie, and, even 

 in that area, although it is true that the scale has increased considerably during- 

 1900, the outside limits of this area have not been extended, and it is only in certain 

 orchards where the insect occurs. In addition to this the majority of the owners 

 of these orchards understand now the danger of neglecting to treat their trees, and 

 are adopting vigorous measures to control the pest. The area may be described in 

 general terms as that part of Ontario where the peach can be grown commercially. 

 All reports of the occurrence of the San Jose Scale in other provinces are erroneous- 

 The only other province where it has ever been found living on trees, is British 

 Columbia ; this was some years ago, and Mr. R. M. Palmer, the official Inspector of 

 Fruit Pests, expressly writes on this subject : — 



' Victoria, B.C., November 21. — You will be glad to know that there is no San 

 Jose Scale in the province. Reports of the presence of this dreaded pest from Salt 

 Spring Island and Cowichan district, upon investigation, proved to be unfounded. 

 The " scare " arose from the fact that many apples affected with the " leaf -spot-fungi "" 

 developed a red-spotted appearance somewhat like the discoloration of the fruit 

 caused by San Jose Scale.' — R. M. Palmer. 



An, important step with regard to this insect was taken by the Hon. Minister 

 of Agriculture last spring in putting through an amendment to the San Jose Scale 

 Act, by which under certain restrictions nursery stock was allowed to be imported 



