15 



EFFECT ON CURCULIOS. 



I have BOW merely to recall the results witli respect to curculic 

 injuries to the apple, derived frohi our last year's work, by which, 

 it will be remembered, it appeared that about half the damage 

 done by curculios was prevented by the Paris green. We kept a 

 similar account of the curculio injuries this season, but their num- 

 bers were so completely insignificant as to give us no sujfficient 

 basis for computation, neither check nor experimental trees showing 

 usually more than one or two per cent, of injury. It consequently 

 remains for us to determine, another year, the effect upon curculio 

 injuries of sprayings made only early in the season, while the 

 fruit is small. As the curculios' work is distributed over a much 

 greater interval than that of the first brood of the codling moth, 

 the arsenical poisons, early applied, are much less likely to affect 

 it in any important way. 



I think we are justified, however, in this important conclusion; 

 that the incidental benefit to the crop by such protection against 

 the curculios as our sprayings gave, and especially such prevention 

 of damage to the foliage as we know to be thus afforded, will fully 

 compensate for the small expense of the Paris green application, 

 which, made on a large scale, with suitable apparatus, only once 

 or twice a year, must fall below an average of ten cents a tree. 



CONCLUSION. 



The experiments above described seem to me to prove that at 

 least seventy per cent, of the loss commonly suffered by the fruit 

 grower from the ravages of the codling moth or apple worm may 

 be prevented at a nominal expense, or, practically, in the long run, 

 at no expense at all, by thoroughly applying Paris green in a spray 

 with water, once or twice in early spring,, as soon as the fruit is 

 fairly set, and not so late as the time when the growing apple 

 turns downward on the stem. 



Finally, I ought to add that my results are confirmed in general 

 by the only other experiment that I know of in which the apples 

 were examined with sufficient care and detail to permit a calcula- 

 tion of ratios of benefit. Last year, at the New York Agricultural 

 Experiment Station, Mr. Goff, one of the officers of the station, 

 sprayed six trees three times with Paris green, and brought them 

 into comparison with four check trees not sprayed. The results of 

 his experiment, as given in the Fourth Annual Report of the New 

 York Agricultural Experiment Station, pp. 218-220, were to the 

 general effect that sixty-nine per cent, of the apples were effectively 

 I)oisoned, and- that the loss by the codling moth was consequently 

 diminished in that ratio. The whole number of apples examined 

 in the course of his observations was 9,198- 



