THE CODLING MOTH ON PEARS IN CALIFORNIA. 



41 



Table XXXV. — Degree of infestation and relative infestation at different places of 

 entrance by codling-moth larvx. Plats I-IV, Suisun, Cal., 1910. 





Total 

 number, 

 of pears. 



1 



Total 

 number 

 of wormy 



pears. 



Degree of infestation. 



Relative infestation at differ- 

 ent places of entrance. 



Plat. 



Total per 

 cent of 

 wormy 

 pears. 



Total per 



cent of 



pears 



wormy 



at calyx. 



Total per 



cent of 



pears 



wormy at 



side and 



stem. 



Total 

 number 

 of worms 

 (100 per 



cent). 



Percent- 

 age of 

 worms 

 entering 

 at calyx. 



Percent- 

 age of 

 worms: 



entering 

 at side 



and stem. 



Plat I, sprayed Apr. 

 6, May 4, and June 

 16 



7,290 

 6,538 

 6,381 

 5,941 



423 

 1,865 



899 

 5,651 



5.80 



- 28. 52 



14.09 



95.12 



1.783 

 19.270 



6.065 

 89. 143 



4. 019 

 9.250 

 8.024 

 5.975 



423 

 1,865 



899 

 5,651 



30.73 

 67. 56 

 43. 05 

 93.72 



69.27 



Plat II, sprayed May 

 5 and June 16 



Plat III, sprayed 

 Apr. 7 and June 17. 



Plat IV, unsprayed 

 check 



32.44 

 56. 95 



6.28 







Table XXXVI. — Degree of infestation and relative infestation at different places of 

 entrance by codling-moth larvae. Plats I to III, inclusive, Concord, Cal., 1909. 





Total 

 number, 

 of pears. 



Total 

 number 

 of wormy 



pears. 



Degree of infestation. 



Relative infestation at differ- 

 ent places of entrance. 



Plat. 



Per cent 



of wormy 



pears. 



Per cent 



of pears 



wormy 



at calyx. 



Per cent 



of pears 



wormy at 



side and 



stem. 



Total 

 number 

 of worms 

 (100 per 



cent). 



Percent- 

 age of 

 worms 

 entering 

 at calyx. 



Percent- 

 age of 

 worms 



entering 

 at side 



and stem 



Plat I, sprayed Apr. 

 17, May 10, and 

 June 29 



13,219 

 14,290 

 13,943 



379 

 7,581 

 1, 731 



2.86 

 53. 05 

 12. 415 



0.938 



39. 181 



7.954 



1.929 



13. 869 



4.461 



379 

 7,581 

 1,731 



32.72 

 73.86 

 63.97 



67. 28 



Plat II, unsprayed 

 check 



26.14 



Plat III, sprayed 

 Apr. 18 and June 29. 



36.03 



For the best results in obtaining fruit free from worms, it is desir- 

 able to spray three times, but if only two applications can be put on, 

 the two early treatments give far better results than any other two 

 sprayings. 



COMMERCIAL RESULTS FROM SPRAYING. 



Contra Costa County, 1909. 



The 15-acre Bartlett pear orchard belonging to Mr. George Whit- 

 man and located in the central part of Ygnacio Valley, Contra Costa 

 County (see Plate III), was used for this work in 1909. The trees 

 are large and well cared for, comparing favorably with the average 

 California pear orchard. 



The larger part of the orchard was included in Plat I as a demon- 

 stration. Four rows across the middle of the orchard were left 

 unsprayed for comparison. Plat III consisted of six rows across 

 the north end of the orchard. 



