130 Bulletin 142. 



Apple-trees have been sprayed with similar substances. In 1878 

 Cook sprayed an apple-tree weekly from May 15 till the last of June with 

 a strong solution of soft soap, with the lesults that not a single apple 

 was wormy, while an unsprayed tree had nearly three-fourths of its fruit 

 infested. Whether the strong smell of the soap kept the moths away, 

 whether the eggs were killed, or how the solution affected the insect, is 

 not suggested. Goff has sprayed apple-trees with kerosene emulsion once 

 (June 11) and with McDougall's Sheep Dip twice (May 25 and 30), but 

 with little or no effect on the codling-moth. 



It may be possible to reach the eggs with a spray in Nebraska 

 where they seem to be laid on the leaves, but our experience in trying 

 to kill the eggs of insects leads us to fear that it will take a stronger 

 mixture than the plant will stand to accomplish the desired result. 

 Whether the eggs can be reached as readily when they are laid on the 

 fruit, can be determined only by experiment. On the whole, we 

 doubt if the codling-moth can ever be combated in its egg stage 

 nearly so successfully and easily as at some other time. 



Cati We Reach the Pupce ? 



As the pupal period lasts only about two weeks, and is passed in 



the cocoon hidden in some crevice of the bark or in store-rooms, it 



offers but little opportunity for attack. Many pupae are killed during 



the summer when the " banding " system (to be discussed later) is 



thoroughly carried out. Many of them could also be killed in the 



spring in store-rooms by fumigating the room, as suggested by Wier of 



California, with carbon bisulphide or hydrocyanic acid gas. But the 



insect can be just as effectually gotten at while it is yet a caterpillar, 



or in the fruit room, even after the moths have emerged ; so that, 



although the pupae can be reached to a limited extent and killed, we 



can fight the insect more easily and more successfully at some other 



time. 



How to Kill the Apple-worm or Caterpillar. 



Having discussed the possible chances of reaching the insect in its 

 moth, egg, and pupal stages, we now turn our attention to combating 

 it in its more vulnerable stage, as an apple-worm. From the time the 

 caterpillar leaves the egg until it is snugly ensconced in its cocoon, it 

 can be reached in several different ways, none of which, however, are 

 a complete success. 



