THE CODLING MOTH ON PEARS IN CALIFORNIA. 



33 



in normal pears do not close up so quickly as in the case of the apple. 

 The blooming period of pears in California is usually very much 

 longer, sometimes lasting from three to five weeks from the first to 

 last appearing blossoms. There is also a " second crop" of fruit 

 which is somewhat later than the other and longer stemmed. It is 

 noticeable that the calyx lobes on this second-crop fruit close up 

 tightly very quickly after the shedding of the petals. As a large 

 percentage of the first-brood worms enters the fruit through the 

 calyx, it is necessary to have poison in the calyx cups before they are 

 closed. The first larvae begin to hatch some three to five weeks after the 

 blooming period is over. At 

 least one and preferably two 

 thorough sprayings should 

 be given before this period 

 of hatching of the larvae. 



Opportunity was offered 

 during the season of 1909 to 

 test the value of two and 

 three treatments on pears 

 and in 1910 a larger set of 

 experiments, to determine 

 the number of applications 

 most efficient and the value 



Ot each as Compared With FlG- 15 —Weekly emergence of codling moths from larvae 

 no treatment at all Was collected from banded apple trees at San Jose, Cal., 1909. 



carried out. The results of 



these and certain other observations are given in the following pages. 



EFFECT OF SPRAYS ON PLACES OF ENTRANCE INTO PEARS BY LARVAE. 



Records were kept throughout both seasons for the entrance holes 

 of all the larvae in the fruit of 10 trees in each block used in the 

 spraying experiments. 



It is interesting to note the places of entrance in the fruit by the 

 larvae, the effect of the different applications on the comparative 

 percentages of worms entering at the calyx and at the side and stem, 

 and where the greater number of larvae was killed. These data are 

 given in Tables XIX to XXXIII, inclusive. (Tables XIX to XXI 

 are the records from the 1909 experiments at Concord, Cal.; Tables 

 XXII to XXIX, the records from the 1910 experiments at Walnut 

 Creek, Cal. ; and Tables XXX to XXXIII the records from the experi- 

 ments at Suisun, Cal., in 1910.) Only the worms entering at the 

 calyx cavity proper are recorded as calyx worms; all larvae entering 

 the fruit through side, base, and around the stem are recorded under 

 the heading of side and stem. 



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