«92 



THE CANADIAN HORTICULTURIST 



December, 1907 



ing larvae have 'had time to fix them- 

 selves, no danger need be feared." 



Dr. James Fletcher, Dominion Ento- 

 mologist, Ottawa: "I have always 

 held that there is no danger from spread- 

 ing the San Jose scale by means of in- 

 fested fruit as handled in commerce, 

 and particularly is this the case when 

 the infested fruit is coming in at this 

 time of the year to a canning factory, 

 which is practically in an infested 

 district. I would, however, suggest 

 as a further precaution that the boxes 

 or "^baskets be kept away from all 

 growing trees." 



NO DANGER OP SPREAD 



Dr. Charles J. S. Bethune, Professor 

 of Entomology, O.A.C., Guelph: "I 

 do not think that there is any danger 

 of spreading the San Jose scale by 

 means of infested fruits which are im- 

 ported for canning purposes. No doubt, 

 some of the scales are alive when the 

 fruit reaches Grimsby, but as soon as 

 the skin is pared off, it speedily dries 

 and the insects are deprived of their 

 food and starved to death. I do not 

 know what the canners do with the 

 ■waste; probably it is fed to pigs or 

 otherwise disposed of. If thrown into 

 heaps or pits, fermentation would soon 

 take place and would destroy any living 

 scales that there happened to be. 

 With very little care as regards the dis- 

 posal of the waste material, there 

 should be no danger of spreading the 

 scale. At this time of year they would 

 not be moving at all, and it is extremely 

 improbable that any of them would 

 reach a fruit tree." 



Prof. T. B. Symons, State Entomolo- 

 gist for Maryland: "In regards to the 

 ■distribution of the San Jose scale by 

 infested fruit, would state that I do 

 not consider that there is a remote 

 possibility of the pest being dissemin- 

 ated in this manner under the ordin- 

 aty means of moving or transportation 

 ■of fruit." 



Dr. L. O. Howard, Chief, Bureau of 

 Entomology, Washington, D.C. : "There 

 has been from time to time more or 

 less agitation in regard to the possible 

 introduction of the San Jose scale into 

 localities on imported fruit. Although 

 this bureau has kept in close touch 

 with the San Jose scale situation since 

 the introduction of this insect into 

 the east, we have never learned of an 

 instance where the scale has been so 

 established. 



"You will recall that fruit, infested 

 with the insect, was shipped from Cali- 

 fornia to the east for many years be- 

 fore its actual introduction occurred 

 by means of infested nursery stock. 

 Fruit is eaten in such places and the 

 parings and waste material are dis- 

 posed of in such a way that it would 

 "be very exceptional indeed for such 

 fruit, or the young scale that might 

 hatch on them, to gain access to trees 



on which the scale could make lodg- 

 ment. While it is possible that such 

 could occur, the conditions necessary 

 are such as to render it extremely im- 

 probable. In the instance of importa- 

 tion of San Jose scale-infested pears for 

 canning purposes, I would have no un- 

 easiness whatever that the scale might 

 become thus established." 



Mr. H. O. Houghton, Entomologist, 

 Agricultural Experiment Station, New- 

 ark, Del.: "There is very Uttle danger 

 of increasing the distribution of the 

 San Jose scale by means of infested 

 fruit; and this should be especially 

 true in the case you mention, where 

 fruit is shipped into a cold country 

 like Canada in the fall of the year. I 

 have yet to know of the first instance 

 where it has been definitely determined 

 that the distribution of this pest has been 

 increased by means of infested fruits." 



Prof. John B. Smith, Agricultural 

 Experiment Station, New Brunswick, 

 N.J. : "Under ordinary circumstances, 

 I do not think that there is the slight- 

 est danger of spread of the San Jose 

 scale from infested fruit. In the par- 

 ticular case mentioned by you, it all 

 depends upon circumstances. If the 

 cannery is not near a fruit orchard 

 and if the refuse, peelings, and so forth, 

 from the pears are not taken out into 

 an orchard and dumped around the 

 trees, I cannot see any conceivable 

 chance of infestation. At this season 

 of the year the scale is not ordinarily 

 active. On fruit, in a warm place, 

 there might be some breeding. In 

 the open, not one out of 1,000,000 

 larvae would stand the slightest chance 

 of getting upon a tree in condition to 

 reach a stage that would enable it to 

 pass the winter. It would be almost 

 impossible to infest trees at this season 

 of the year from fruit parings even by 

 taking the greatest care to insure that 

 result. Any ordinary care in the dis- 

 position of the fruit would absolutely 

 bar the danger." 



NO RECORD OF INFESTATION 



Prof. M. V. SHngerland, of Cornell 

 University: "I have said many times 

 in print and in public that the danger 

 of disseminating the San Jose scale 

 by means of infested fruit is very 

 slight. There is scarcely one chance 

 in 10,000 that a new infestation by 

 this pest will be accomplished by the 

 introduction of infested fruit only. 

 So far as I know, there is no authentic 

 record of such a new infestation ever 

 having been brought about by infested 

 fruits. One can easily conceive, how- 

 ever, how it might be accomplished 

 in the following manner: If some of 

 the scales on the fruits were mature 

 and young lice were being born, and 

 such a fruit were placed in a tree, some 

 of the young lice might crawl from the 

 fruit on to the bark and establish 

 themselves. It has been suggested that 



the peelings from such infested fruits, 

 if thrown near trees, might easily in- 

 fest them. If recently-born, crawling 

 lice were on such peelings, which were 

 thrown so that they touched the bark 

 of the tree, it, of course, would be pos- 

 sible for some of the young lice to get 

 on to the bark of the tree. While, 

 therefore, it is possible to infest trees 

 by means of infested fruit, there i 

 really very little danger of the San Jose 

 scale being disseminated by this means. 

 The insect is now very widespread all 

 through the United States and Canada, 

 and is constantly appearing in new 

 localities where young orchards are 

 being set. In spite of the precautions 

 of nurserymen and inspectors, even 

 when they claim to fumigate their 

 stock thoroughly, the scale is being 

 shipped into new localities constantly." 



ENTIRELY IMPOSSIBLE 



The Economic Zoologist for Pennsyl- 

 vania, Mr. H. A. Surface, M.Sc, dis- 

 cusses the question as follows: "I take 

 pleasure in replying at once to your 

 letter, asking if in my opinion the 

 San Jose scale can be disseminated on 

 pears or other ripe fruits shipped for 

 canning purposes or for other pur- 

 poses. After a careful consideration 

 of this subject, extending through a 

 period of six years, and after having 

 made experiments along this line and 

 reading all literature possible upon 

 the subject, I am firmly convinced 

 that it is entirely impossible to dis- 

 seminate San Jose scale upon fruits. 

 I conscientiously believe that it is 

 absolutely impossible to spread scale 

 by such means. Laws providing for 

 the destruction of all infested fruits 

 are unjust both to producers and con- 

 sumers as well as shippers, and are 

 based upon ignorance of practical and 

 important scientific facts in nature. 

 While the San Jose scale does live upon 

 green fruit, it either dies or entirely 

 ceases to reproduce when the fruits 

 commence to ripen. It is well known 

 that after it is once fixed it can never 

 free itself and fix again. Thus, the 

 individual specimen found upon fruit 

 could not by any possible means be 

 carried to other fruits or trees and 

 continue to live, and the only possi- 

 bility of such spread would be by the 

 very young (less than two days old) 

 insects produced by the parent and 

 disseminated after arrival at their des- 

 tination. As there is no reproduction 

 by the San Jose scale upon ripe fruits, 

 there is no possibility of this contin- 

 gency. I wish that all entomologists 

 and horticulturists would aid in em- 

 phasizing this important point. I am 

 certain that no man can prove to me 

 anything different from what I have 

 heard written. These statements are 

 posithe and I risk my scientific reputa- 

 tion should I make an error in discuss- 

 ing a thing so important." 



