60 THE REPORT OF THE [ No. 19 



But so far as it has been used it would appear that we have yet much to learn, before we 

 can, with safety, recommend the application of the crude product to the different varieties 

 of fruit trees. That it is efficient in destroying the San Jog6 scale, if it is brought in 

 contact with this insect, seems now quite probable. But the hundreds of dead trees that 

 mark the areas where it has been indscriminately used, point very clearly to the fact 

 that great caution is necessary, and no one is, as yet, able to say just where safety ceases 

 and danger begins Th'^n, too, when no permanent injury is apparent, as in the case of 

 the seedling apples on the grounds of the Ohio Agricultural Experiment Station, at Wooster, 

 Ohio, who can say that this unnatural retardation may not, after the first application 

 prove to be a menace to the life or general vigor of the trees ? It is well known that, in 

 nature, these retardations sometimes occur, but nature seldom, or never, covers the bark of 

 a tree or a ehrab, and then only in part, with vegetable growths like lichens, aad even 

 these are known to be detrimental, a smooth, clean bark being always desirable. 



In the use of refined petroleum, one of the most perplexing phenomena observed was 

 the fact that, equally careful applications, made by the same person, with the same grade 

 of oil, would give almost opposite results. Hence, recommendation of the refined pro- 

 duct for general use has, in many cases, resulted disastrously and brought no little dis- 

 repute to the entomological fraternity of this country. The most that can now be said for 

 the refined product is that a ten to twenty per cent mixture with water constitutes a 

 fairly successful summer wash and destroys the young scale, thereby checking the in- 

 crease and spread until applications of whale oil soap mixtures can be made. 



In the use of theciude product, I have seen some of the most astonishing results 

 obtained, but, as with the refined, I have seen also the most disastrous effects. Peihaps 

 the uncertainty of effects in using crude petroleum in the orchard may be best illustrated 

 by giving the results obtained, this year, by Mr. N. A. Hadden, of Catawba Island. Mr. 

 Hadden used crude petroleum on the strength of recommendations from New Jersey, in- 

 cluding those published by Prof. John B. Smith, and contrary to the advice of some of 

 his neighbors." As I knew nothing of the matter until some weeks after the latest appli- 

 cations, nothing could have been eaid or done by me to in any manner influence Mr. 

 Hadden, who followed his own course, and, I may add, has offered me every facility for 

 observing the final results. 



About 50 peach trees of the Crawford's late variety were sprayed March 10, 1900, 

 with 100 per cent crude petroleum from an oil well near Gypsum, Ottawa County : Dit- 

 tillation B. The spraying was carefully done and none of the petroleum was allowed to 

 run down the trunks of the trees. The effect on these trees was to kill every one of them. 

 Two other blocks of peach trees on which crude petroleum from the same well was used, 

 were also totally destroyed. On the same day, March 10, 1900, six plum and one peach tree 

 were sprayed with crude petroleum from the same well and of samo strength. Two un- 

 healthy plum trees died ; the other four were uninjured, as was also the peach, which not 

 only made a vigorous growth but bore several peaches. Several rows of Smock and 

 Salway peaches were sprayed April 7th with 100 per ceat. crude petroleum, and, though 

 not showing serious injury on May 16th, in July 90 per cent were dead and the remainder 

 fatally injured. Crawford's Late, sprayed March 8th with 10 per cent, crude petroleum, 

 and another block sprayed with a 40 per cent, mixture, were not seemingly injured, but 

 bore no fruit. Eight apple trees and several peach trees, sprayed March 8th with 10 per 

 cent, crude petroleum, were uninjured. 



On the premises of C. W. Shoemaker, at Waterville, Ohio, there stands a Wilder 

 Early pear tree, that for several years was badly affected with the Scurfy Bark louse. 

 The tree was stunted and made little growth each year. Two or three yeirs prior to 1900 

 the tree was sprayed in spring with kerosene emulsion, which killed many of the insects, 

 and the tree afterwards made a better growth than it had previously done. April 2nd, 

 1900, this tree was painted with crude petroleum, the analysis of which I have not been 

 able to secure On August 17tb, 1900, I saw the tree, and the bark still gave good evi- 

 dence, by its colour and shining appearance, of the presence of the petroleum. The growth 

 has been vigorous and the foliage was of the most healthy colour. The Bark-louse seemed 

 to have been quite exterminated. 



On March 23rd, 1900, a row of three year old seedling apple trees, on the Station 

 grounds near Wooster, was treated with crude petroleum of different strength?, applied 

 with a Deming kerosene attachment, the applications being made by two of my assist 



