REPORT OF THE STATE ENTOMOLOGIST I915 4I 



increasing the percentages of perfect fruit. The results, so far as 

 control of the leaf roller is concerned, are not illuminating, since 

 for the plot receiving one spraying the infestation amounted to 

 10.80 per cent, that sprayed twice to 12.50 per cent and that receiving 

 three treatments, 8.09 per cent. It is doubtful if these variations 

 possess much significance and the probabilities are that they can be 

 more easily accounted for by variations in the infestation of the 

 different plots and unavoidable differences in treatment, rather than 

 to the value of late applications for the destruction of this pest. 



The codling moth data are worthy of special comment, since they 

 show unmistakably the benefits resulting from one application 

 just after the blossoms fall and the comparatively small returns 

 following later sprayings. The percentage of wormy apples for 

 the three plots sprayed but once, amounted to 10.15, while that 

 for the plots sprayed twice was 8.86, and for that sprayed three 

 times, 8.24. The difference between the plots sprayed once and 

 twice was only 1.29 per cent in favor of the latter, while between 

 this and the plots sprayed three times, there is a difference of only 

 .62 per cent. These figures are not quoted for the purpose of dis- 

 couraging second and third sprayings for the control of the codling 

 moth, but rather to emphasize the value of the first treatment. We 

 are still of the opinion that control not obtained with the application 

 made just after the blossoms fall, can not be secured in any practical 

 manner by subsequent treatments. 



The past season was exceptionally favorable for the develop- 

 ment of scab, and in the control of this disease we find ample justi- 

 fication for two or even three applications after the blossoms drop. 

 These later treatments should, in our estimation, be given more 

 for the purpose of controlling this fungus than as a check upon the 

 codling moth, though it is by all means desirable to add poison to 

 the fungicide for the purpose of destroying as many codling moth 

 larvae and various leaf feeders as practical. 



SIDE INJURY 



Approximately nine-tenths of the wormy apples on the sprayed 

 trees showed the typical blemish (plate 1) caused by the late-hatching 

 larvae of the first brood. These come from, eggs deposited on the 

 fruit the latter part of June and early in July. The young larvae 

 enter the exposed, smooth surface of the developing apple and 

 excavate a shallow gallery having a radius of approximately one- 

 sixteenth of an inch and frequently marked by a reddish or reddish 

 brown spot. This is probably a manifestation of the leaf -mining. 



