U. S. D. A., B. E. Bui. 80, Part VII (Revised). D. F. I. t, March 30, 1911. 



PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



THE ONE-SPRAY METHOD IN THE CONTROL OF THE 

 CODLING MOTH AND THE PLUM CURCULIO. 



By A. L. Quaintance, 

 In Charge of Deciduous Fruit Insect Investigations, 



AND 



E. L. Jenne, E. W. Scott, and R. W. Braucher, 



Engaged in Deciduous Fruit Insect Investigations. 



INTRODUCTION. 



The so-called one-spray method of spraying for the codling moth 

 on apples consists essentially in making the application following the 

 dropping of the petals so thorough that it will result in the practical 

 extermination of the first brood of larvae, subsequent treatments, 

 therefore, becoming unnecessary. This method of spraying has 

 come into considerable use in the Northwest following the investiga- 

 tions of Dr. E. D. Ball, in Utah, and Prof. A. L. Melander, in Wash- 

 ington, and its applicability for the control of the codling moth under 

 eastern conditions has been strongly urged. The subject has already 

 received attention at the hands of several eastern entomologists, 

 notably Gossard, in Ohio, Sanderson, in New Hampshire, Felt, in 

 New York, and Rumsey, in West Virginia. It is not within the scope 

 of the present paper, which is in the nature of a preliminary report, 

 to review the present status of the one-spray method. On the whole, 

 however, it has appeared to the writers from a study of the experi- 

 ments thus far reported as bearing directly upon the control of the 

 codling moth, that most of these have been more or less inconclusive 

 as not having fully met the conditions stated to be essential for suc- 

 cessful one-spray work. The indispensable requisite is stated to be 

 the placing of necessary poison in the inner calyx cup. By referring 

 to figure 33 the structure of the calyx end of a young apple may be 

 noted, namely, that there are two cavities, one above and one below 

 the stamen bars or filaments. The observations of Doctor Ball led 

 him to believe that the great majority of codling-moth larvae in seek- 

 ing entrance at the calyx end of the apple enter through the lower 



113 



