638 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



ment followed in the P.ast were concludod ;i( <lie close of the growing 

 season of 1911, and a full report on the subject is now in the course 

 of publication. It was determined that a high degree of efficiency 

 in the control of the codling moth and plum curculio was obtained 

 from a single application of spray made immediately after the fall- 

 ing of the petals. In the case of varieties of the apple little subject 

 to fungous diseases, the one-spray method would appear to be of 

 much value under eastern conditions. The investigation further 

 developed the very important point of the necessity for greater 

 thoroughness in spraying at the time of the falling of the petals 

 than has generally been followed by orchardists. 



Owing to the prevailing diiferences of opinion between certain 

 eastern and the western entomologists in regard to the condition at 

 spraying time of the structures at the calyx end of the apple, a care- 

 ful inquiry has been begun in Michigan and New Mexico, represent- 

 ing humid and arid conditions, respectively, to determine the con- 

 dition for many varieties of apple of the so-called calyx cup during 

 the two or three weeks subsequent to the falling of the petals. This 

 information will have a distinct bearing on the character of spray- 

 ing to be done to best insure poisoning the calyx cup, the prime 

 essential in codling-moth control. 



Demonstration spraying for the codling moth, as in former years," 

 is being carried out in connection with other work in some of the 

 bureau's field stations, notably in Michigan, New Mexico, and, during 

 1911, in Delaware. This work has been much appreciated by_ or- 

 chardists in the neighborhoods where located and has resulted in a 

 distinct improvement in the character of work done by them in their 

 own orchards. 



The investigations of the codling moth throughout the Appala- 

 chian Mountain region, begun in the spring of 1911, are being con- 

 tinued. Last season's work indicated the importance of a thorough 

 knowledge of the insect throughout this region, due to the variation 

 in its behavior under the dillerent conditions of altitude in which 

 apples are grown. Band records and life-history observations are 

 being made at 10 or 12 different stations located at representative 

 points in western Maryland, Virginia, and West Virginia. 



THE GRAPE LEAFHOPPEE. 



The grape leafhopper has during recent years become very trouble- 

 some in vineyards in the Lake Erie Valley, and special effort has 

 been made to perfect a treatment for its control. The spraying ex- 

 periments and demonstrations carried out in vineyards in 1911 have 

 shown conclusively that great benefit may be obtained by the proper 

 use of nicotine sprays directed against the immature stages or 

 nymphs of this insect. This work, hov>ever, has shown the necessity 

 of a more detailed knowledge of the life history of the pest, especially 

 as to the period over which the insect in the immature stages will be 

 found on the vines, and the present season's work will be devoted 

 largely to questions in its life history as contributing to a more ef- 

 fective spraying schedule. A report has been prepared and sub- 

 mitted for publication, dealing with the results of field experiments 

 carried out during the growing season of 1911. 



