AND OTHER INJURIOUS INSECTS OF I907 AN'I) I()o8. 



79 



lower of the two cavities, see Fig. 29, b and bl. The young larva 

 enters the apple by eating through the floor of the lower cavity. Ball's 

 idea was to get the poison lodged, in sufficient cjuantity in the lower 

 cavity where it would do some good. To accomplish this he sprayed 

 from above, while the apples were still erect. Fig. 29, a. But for a 

 few days after the petals fall, these stamen "bars" are so tightly 

 pressed together as to make it very difficult for the liquid to penetrate 

 to the lower cavity. By waiting a week or ten days, even though the 

 calyx lobes are closing at that time, these bars have shrunk. Fig. 29, c 

 and cl, enabling a careful workman to place a big dose of poison in 



Fig.L'ii. a. iiftei- Slingeiiand; b, bl, c, cl, after Ball. 



the lower chamber, where it is needed. The nozzle should be held 

 above the apples, and made to give, not a mist, but a forcible and sub- 

 stantial spray, directly down upon the fruit. Later than this, how- 

 ever, spraying with these principles in view would be of little avail 

 because the calyx lobes are almost completely closed. Ball's work 

 shows that enough poison is retained from two early sprayings to kill 

 an average of ninety per cent of the worms of the first brood and 

 seventy-four per cent of the second brood. To accomplish good results 

 the spray must be a forceful one used abundantly, and from above the 

 fruit. 



