New York Aguicultuual Experiment Station. 535 



places from year to year for such insects as the canker worm, 

 and hence are a source of danger to the fruit growing industries 

 in the vicinity. In some instances, however, the orchards visited 

 had been sprayed, but judging from their appearance and from 

 some of the spraying done while the writer was present, the work 

 was of little value. 



Judging from our observations, there are three principal rea- 

 sons why the canker worms were not held under better control 

 in infested orchards in western New York last year. First, the 

 application of Paris green was not begun early enough in the 

 season. It is probably not unjust to say that in very many cases 

 the spraying machine was not taken into the orchard until the 

 canker Vvornis were well established, while the work should have 

 been begun as soon as the first young worms appeared. Second, 

 the spraying was not done thoroughly enough, and third, there 

 were not a sufficient number of applications of the poison made. 

 In some instances, only one or two applications of the poison 

 had been made where at least three or four would not have been 

 too many. We may also add that in some cases an inferior 

 quality of Paris green was used. 



Among farmers it is a common statement that Paris green 

 will not kill canker worms. We found it especially so with 

 those whose orchards had suffered severely from this insect. 

 The efficiency of Paris green as a remedy for canker worms we 

 need not discuss in detail here. We did see some orchards, how- 

 ever, which had been carefully sprayed and which 

 were in fine foliage when neighboring orchards were 

 almost without a leaf. Plate XXXVIII is from a photograph of 

 a portion of two orchards. The one on the right had been 

 sprayed, while the one on the left had not been sprayed. An 

 actual view of the orchards showed a much greater difference iu 

 the amount of foliage than is shown in the plate. Plate XXXIX 

 is from another view in the orchard which had not been sprayed. 

 Both of the photographs from which these plates were made 

 were taken early in June. 



