INSECTS 201 



Second spraying. The difference in the time of blooming of 

 different varieties of apples, and even of fruit clusters on individual 

 trees, makes it certain that when the calyx end of a certain per- 

 centage of the fruit has advanced to the proper conditions for the 

 first spraying, the remainder — perhaps the greater part — is yet 

 in bloom. A second spraying, a week or ten days later than the 

 first, is necessary in order to reach these belated blooms before 

 their calyxes close. It is also desirable to apply to the fruit a heavy 

 coating of arsenical spray material as quickly as possible on account 

 of the early and great activities of curculio. The second application 

 is more valuable if applied with a view to treating belated blooms 

 than if applied arbitrarily three weeks after the first spraying. 



As it is not practicable to consider a schedule of 

 spraying for the codling moth independent of apple 

 diseases, it is recom- 

 mended that where 

 diseases are preva- 

 lent the arsenate of 

 lead of the second 

 spraying — whether 

 applied one week 

 or three weeks after 

 the first — be incor- 

 porated into a fun- 

 gicide. 



Third spraying. The third spraying of lead should be applied, in 

 combination with Bordeaux mixture, six weeks after the first. To 

 50 gallons of Bordeaux mixture should be added 1 1 pounds of lead. 



Plum curculio (Conotrachelus nenuphar, Herbst). As a perennial 

 problem of apple-growing, the plum curculio takes the second 

 place in point of economic significance. In spite of its name its 

 dietary range includes other fruits than the plum. In addition to 

 apples, peaches, and plums, it feeds upon and breeds in cherries, 

 pears, and other cultivated fruits. It is recognized as the principal 

 insect enemy of the peach, and was not successfully combated until 

 the introduction of arsenate of lead as a means of control. In 

 peaches, when unchecked, it finds a most congenial environment 

 for breeding, and there reproduces itself with amazing multiplicity. 



FlG. 86. Work of curculio (1 and 2) and apple weevil (3) 

 (Photograph by F. E. Brooks) 



