138 Bulletin 142. 



enter at this point, led to the recommendation to spray just after the 

 blossoms fell. The experience of those who have sprayed has con- 

 firmed this conclusion, and it is now the universal practice to try and 

 make the first application at this time. As Mr. Lodeman lias put 

 it : '' The falling of the apple blossoms is the signal for the use of 

 arsenites in the destruction of the codling-moth." Our observations 

 would indicate that a safe rule will be to spray the fruit at any time 

 within a week after the blossoms fall; if it rains within a few days 

 repeat the spray at once. The reason why and the great importance 

 of spraying at this time is discussed under the next heading. Where 

 there are both early and late varieties in an orchard, it may be neces- 

 sary to spray some trees before others ; usually there is not enough 

 difference in time between the dropping of the blossoms from late and 

 early varieties but that all trees can be sprayed the same day. 

 Although experiments demonstrated that it was necessary to spray at 

 this time to secure the best results, yet but few really understood the 

 "why" of it; that is, just how it did or could affect the insect when 

 applied at this time. 



How the poiso?i affects the eodling-moth. — Those who critically exam- 

 ine the literature will be surprised to find how few definite statements 

 there are regarding this very important phase of the question of com- 

 bating this insect. It seems to have been the current notion for some 

 time that the poison spray not only killed some of the insects, but that 

 it also acted as a preventive in some way. It was in consequence of 

 the repeated requests of Mr. Lodeman for information on this point 

 that we began studying this old enemy, about which most of us have 

 thought there was nothing new to be learned. We were surprised to 

 find several times that our observations would not agree with the stereo- 

 typed notions regarding the life and habits of the insect at the time 

 when fruit-growers were spraying to kill it. Our first surprise was to 

 find that the moths did not begin to emerge in considerable numbers 

 until several days after the blossoms had fallen, and consequently we 

 were unable to find any eggs until the blossoms had been off for a 

 week or more. 



Meanwhile, we had been watching the development of the young fruit 

 and had seen something of great importance to fruit-growers and which 

 seems to have escaped the notice of most experimenters ; we have seen no 

 mention of it except by Gillette and Munson. Just after the petals fell, 



