REPORT OF THE STATE ENTOMOLOGIST I918 I7 



INJURIOUS INSECTS 

 CODLING MOTH 

 Carpocapsa pomonella Linn. 



Experimental work to test the relative efficiency of one, two and 

 three applications was continued in the orchard of G. W. Mead, 

 Barker. A general description of the orchard and the location of 

 the plots has been given in the Report for 19 17 (see pages 18 and 

 19) and need not be repeated here. 



The first application was made May 27th and 28th. Two and 

 one-half pounds of paste arsenate of lead were used to 150 gallons of 

 water and a gallon of standard lime sulphur added to each 40 of the 

 spray. This, the regular calyx application, was made to three plots, 

 300 gallons being used and some burning of the foliage resulted. 

 The application was supervised by J. B. Achilles. 



The second treatment was given to plots i and 2 July 9th, 170 

 gallons of spray being used . This was followed by a serious yellowing 

 and dropping of the foliage. The work was supervised by L. F. 

 Strickland. 



The third spraying was given July 26th, to plot 3, 60 gallons of 

 spray were used. The proportions were the same as in the earlier 

 treatment. Throughout the work a Gilford spray gun was employed 

 and the pressure was maintained at 22 5 pounds. 



The apples were picked in early October and classified by L. F. 

 Strickland, agent. Department of Farms and Markets. He was 

 assisted in this work by J. B. Achilles and T. T. Neill of the same 

 department. The fruit on the six trees of each of the three plots 

 and that on the two check trees was carefully classified, and an 

 examination of the complete data shows in the case of plot i , sprayed 

 once, a codling moth infestation ranging for individual trees from 

 6.18 to 18.28 per cent or for the plot 10.17 per cent wormy fruit. 

 In plot 2, the ranges were from 3.7 to 19.45 per cent of wormy apples, 

 the plot per cent being 10.66. Similar figures for plot 3 showed a 

 variation from 5.34 to 15.95 per cent, the per cent for the plot being 

 9.10. These wide differences are due in part to great variation in 

 the yield and probably also to the difficulty in doing equally thorough 

 work with a nozzle which demands very rapid operation, if one 

 would avoid overloading the trees with spray. With these facts 

 in mind it was deemed best to make selections from each plot, taking 

 trees which bore at least a moderate crop and those which did not 

 deviate widely from what we judged to be the normal. This latter 

 consideration resulted in the elimination of tree F on plot 3 because 



