U.S. D. A., B. E. Bul. 80, Part VIT (Revised). D. F. I. I., 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 
EK. L. JeEnNneE, E. W. Scort, anp R. W. BraucHErR, 
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 larvee in seek- 
ing entrance at the calyx end of the apple enter through the lower 
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