The Codling Moth. 26 



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worms produced. In the Pajaro Valley this does not occur, however, until 

 about picking time, except in the latest varieties. 



In some parts of this region there is not sufficient advantage in spraying 

 for the first generation of worms to make it desirable to go to that trouble. 

 Allien spraying is necessary, the time may be determined by gathering a 

 quantity of winter worms in their cocoons and placing them in a breeding 

 cage. This may consist of a fruit jar with a piece of cheese-cloth tied over 

 the mouth. This jar should be placed in the orchard where the sun will not 

 shine upon it, or rain wet the contents, but where the other conditions are the 

 same as though the cocoons were on the tree. By examining this jar weekly 

 and removing moths that emerge one may determine very accurately the time 

 when spraying should begin and whether more than one treatment is necessary 

 to cotrol the worms of the first generation. 



Most recent writers upon the codling moth have insisted upon the necessity 

 of placing the poison in the calyx cup before it closes. Our observations indicate 

 the soundness of this practice where the entrance is made at this point, but it 

 will not amount to as much in the Pajaro Valley as in some other regions, since 

 a very small per cent actually enter the fruit at this point, possibly on account 

 of the comparatively late emergence of the first generation of moths. 



The blossoming time also extends with us over a long period, so that more 

 than one spraying is necessary to fill every cup and the first spraying must be 

 made while the trees are in full bloom. In most regions these first sprayings 

 are probably profitable, though in the region under observation such a small 

 percentage of the worms entered at the calyx end as to make this somewhat 

 doubtful. Our spraying experiments did not cover this point as fully as could 

 be desired and it will be gone into more fully next year. 



As a result of these studies our positive recommendations in the matter of 

 time of application for the codling moth is an annual program as follows : 



Ii-'ii-j5t. — Spray as soon as the oldest blossoms have dropped their petals and 

 repeat once or twice if necessary to reach every blossom cup. 



Second. — Spray as soon as spring brood of moths begin to fly. as determined 

 by breeding jars, and repeat if the hatching period extends over three weeks. 



Third. — Spray as soon as worms appear under the bands and continue 

 about every three weeks until the winter worms that do nut pupate replace 

 the summer form. 



In some regions the first, or first and second, set of sprayings can be 

 omitted. Whether this can be safely done in any particular orchard can be 

 determined by leaving a row unsprayed and keeping a careful band record, 

 and if there is an appreciable larger number of worms under the bands on the 

 unsprayed trees these sprayings are necessary. 



The above described rational spraying program ought to replace the present 

 rather empirical system. 



THE CODLING MOTH. 



By Prof. Clarke, University of California. Address delivered before the North- 

 west Fruitgrowers' Association, Portland. January, 1UU4. 



jl/r. President, Ladies and Gentlemen : 



I have had the pleasure of presenting this paper by Prof. Woodworth, anJ 

 I will say for myself that I came here with the hope of learning something 

 and not to teach you people of the Pacific Northwest. 



In regard to the work that we have done in the Pajara Valley during the 

 past season, I would say that we have experimented over a territory some sixty- 

 five miles north and south. We have had all the varying climate conditions 



