TWENTY-EIGHTH FRUIT-GROWERS' CONVENTION. 



147 



of attack is necessary. Preparations that kill by contact are necessary; 

 whale-oil soap, the kerosene emulsion, or the resin wash are usually 

 effective; and where these will not reach, or are ineffective, hydrocyanic 

 acid gas will do the work. 



It is not improbable that in time we shall be able to restore the balance 

 of nature by the discovery, introduction, and distribution of parasitic 

 and predaceous insects so that our present cumbersome, inefficient, 

 and expensive methods of fighting pests will be largely, if not wholly, 

 rendered needless. We have already by this means greatly reduced 

 the number of our destructive insect enemies and are keeping those that 

 we have reached in a state of "innocuous desuetude." At present there 

 are not over a half dozen really serious pests of deciduous fruit trees, 

 among which are the codling-moth, the woolly aphis, the peach-root borer, 

 and the various forms of aphids. For the latter, the ladybirds are an 

 efficient check, and while the pests appear in large numbers at some 

 seasons, they also as rapidly disappear. 



Even under the most favorable conditions, however, we can never 

 hope to be free from insect pests, for there will always be occasional 

 serious outbreaks; but with their natural checks thoroughly established, 

 these outbreaks will be spasmodic and not continuous, as in some cases 

 at present, and will continue only until their check can again overtake 

 them. In the meantime, it behooves our orchardists who would have 

 marketable fruit, or often any fruit, to watch and spray. 



PRESIDENT COOPER. The papers you have heard read are all 

 that are to be read at this morning's session, and they are now open for 

 discussion. 



PROFESSOR COOK. I have listened with a good deal of interest 

 to this admirable paper which has just been read. In regard to the 

 bacterial pests mentioned last, I think, as Professor Huxley said about 

 the origination of organic from inorganic, that he had a scientific faith 

 that it was so. So I guess most of us have a scientific faith that peach 

 yellows are bacteria. Now, when the peach yellows came to St. Joseph, 

 Michigan, the very unfortunate idea of "hush up" was in everybody's 

 mind, and they said, "say nothing." As a result, the peach orchards 

 all went to ruination and barely to-day have they recovered. While in 

 South Haven the idea was to "cut back and root up," and to-day they 

 have splendid orchards. I have known a single orchard to sell $11,000 

 worth of peaches in that region. Where we found those blights, even 

 though we may not know what they are, the matter of rooting up and 

 cutting back is exceedingly valuable. 



I wish to speak of another thing which comes in here very oppor- 

 tunely. The gentleman says that in fighting the sucking insects he 

 would use the soap solutions and use the kerosene emulsion, which I 



