REPORT OF THE DIRECTOR I919 23 



The series of experiments to determine the relative efficiency of 

 the several sprays for control of the codling moth in the western 

 part of the State have been continued. The most marked results, as 

 were to be expected, were obtained from the first or calyx application 

 and while the reduction in wormy apples was decidedly less in the 

 case of the second and third treatments, there was no question but 

 that these additional sprays are amply justified by other considera- 

 tions. 



Tests of the value of nicotine in the spray applied about three 

 weeks after blooming, indicate little benefit in the destruction of 

 adult codling moths or recently deposited eggs and so far as this 

 insect is concerned, the inclusion of this costly insecticide in the 

 second application can not be advised though it is undoubtedly very 

 beneficial when aphids are numerous. The data in relation to this 

 insect secured the past season are discussed in some detail in the 

 body of the report. 



Shade tree insects. The past season was marked by the dis- 

 covery of another pest in the United States upon which has been 

 tentatively bestowed the common name of elm ribbed cocoon-maker. 

 It is with very little question the European Bucculatrix 

 u 1 m e 1 1 a Zell. It has been reported as seriously injuring 

 European elms in the Rochester parks. 



A recently introduced willow leaf beetle, Plagiodera 

 versi colora Laich., was brought to notice the past season on 

 account of the serious injury to weeping willow foliage in Nev/ 

 York City. It is also known as a pest of poplar and may possibly 

 be of some service in checking the indiscriminate planting of this 

 somewhat undesirable shade tree. 



The elm leaf beetle, Galerucella luteola Mull., was 

 somewhat injurious here and there in the State, particularly outside 

 of areas where it was very destructive lo to 15 years earlier.' This 

 is probably due in part to better control in localities where the insect 

 has caused the most damage and partly to the somewhat unfavorable 

 climatic conditions of recent years. 



The bronze birch borer, A g r i 1 u s a n x i u s Goiy, continues 

 its nefarious work and here and there throughout the State many 

 magnificent birches are succumbing to the work of this borer. It is 

 only a question of time before all the cut-leaved birches will suc- 

 cumb unless they are systematically protected. 



A compilation of the office records of the last twenty years indi- 

 cate a probable biennial life cycle for the large, strikingly colored 

 Say's blister beetle, Pomphopoea sayi Lee. This insect 



