April, '12] 



QUAINTANCE: CODLING MOTH 



161 



of Mr. E. W. Scott, during 1911, in Michigan, the employment of 

 high pressure and a coarse spray did not result in poisoning the inner 

 calyx cup, except in occasional instances. It would appear on the 

 whole that under eastern conditions, the spray is not forced to an 

 appreciable extent below the stamen bars, though the extent to which 

 this is done will vary with the age of the apples when treated, and 

 perhaps with the variety in question; more information is needed 

 on this point. 



Relating directly to this topic is the question of whether it is neces- 

 sary to place the poison in the inner calyx cup; it would appear, in 

 fact, that such is not the case. Observations by numerous experi- 

 menters, as shown above, on a single application of a coarse spray, 

 under high pressure, show that in but comparatively few cases is the 

 posion forced into the lower cavity. The results from the one-spray 

 are on the whole excellent and fairly uniform, which indicates clearly 

 that the young codling moth larva feeds mostly in the outer calyx 

 cavity. Specific confirmatory observations are at hand on this point, 

 notably those made by Professor Slingerland (I.e.), and Professor 

 Sanderson (I.e.). 



The One-Spray Method. The above considerations relate closely 

 to the one-spraj' method. Data on the efficiency of a single applica- 

 tion after the falling of the petals is tabulated below: 



SUMM-^RY STATEMENT ON RESULTS OF ONE-SPRAY METHOD AGAINST CODLING MOTH AND 



PLUM CURCULIO 



Experimenter 



Codling Moth 



Plum Curculio 



Unsprayed. Sprayed Unsprayed. 

 Per cent once. Per Per cent 

 sound. I cent sound. .=ound. 



Gos-'ard . 

 Rumsey . 

 Felt. . . . 



Bureau of Entoinology: 



(1) Virtrinia 



(2) Virginia 



(3) Arkansas 



(4) Miciiigan 



(5) Delaware 



(6) Kansas 



(7) Michigan 

 (8; Virginia 



1909. 

 1909. 

 1909. 

 1909. 

 1911. 

 1911. 

 1911. 

 1910. 



.Averages of percentages . 



91.60 

 97.40 

 97.23 



84.07 

 91.68 

 92.76 

 93.61 

 92.83 

 84.16 

 87.05 

 99.01 



02.86 



45.80 

 65.90 

 68.78 



53.02 

 54.00 

 66.74 

 77.79 

 43.40 

 30 20 

 52.73 

 84.49 



58.44 



73.96 

 57.90 

 86.34 

 97.54 

 85.69 



67.90 



54.02 

 27.23 

 8.85 

 87.42 

 65.13 



51.76 



