70 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 2 



to show that although theoretically desirable, spraying the foliage 

 gives no practical benefit. 



4. "Our apples attain a surprisingly large size before the first brood 

 of larvce begin to enter the fruit. Thus a large part of the surface 

 will be unprotected by the poison." 



Coming to Washington with the idea that the second spraying- 

 should follow ten days after the first we were surprised to note that 

 the onset of the first brood of worms occurs from a month to seven, 

 weeks after blossoming time, and of course by that time Washington 

 apples are also surprisingly large. But that point has little to do^ 

 with the validity of calyx spraying, for, by the time of the third brood,, 

 apples are still larger, yet the first spraying gives just as much pro- 

 tection then as ever. The average of all our counts in unsprayed 

 orchards shows 90% of the late larvae entering through the calyx. 

 Theoretically, therefore, spraying the calyx alone should destroy 90% 

 of all codling moth larvas. Practically, however, probably because of 

 the natural mortality of the insect, the number is nearly 100%. 



3. '[In every case where the young larva had entered the apple at 

 the calyx end it had stopped to feed in the outer calyx cavity. I was 

 unable to obtain a7iy evidence that the larvce worked their way into the 

 lower calyx cavity without first taking several meals in the outer cav- 



ity." 



Undoubtedly some larvie do feed in the outer cavity, but that is: 

 not the point. The important fact remains that some larvfe take their 

 first meal in the lowermost cavity, and in the matter of practical spray- 

 ing our main attention must be directed to them if we are to extermin- 

 ate the first brood. When poison is forced into the lower calyx cup 

 there is enough in the outer cup and on the leaves to take care of what- 

 ever larvffi may choose to feed there. But when a mist-spray is used 

 for the outer cavity alone, some larvae, a great many even, reach the 

 lower cavity unpoisoned, and then we cannot hope for 100% of suc- 

 cess with one — or even more than one — spraying. The western- 

 method aims to reach the most inaccessible part of the flower. Only 

 by that method can one spraying be depended on under the adverse 

 conditions prevailing in this three-brooded district. 



Director Ball* has already pointed out that "an examination of 

 thousands of apples with this point in view showed that in 97% or 

 98% of those classed as 'calyx wormy' the entrance had been made 

 from the lower part of the lower cup." Our own observations cor- 



"U. S. Bur. Ent. Bui. 67, p. 74. 



