CONTROL OF CODLING MOTH IN ARID REGIONS. f)5 



conservative, as all other authors have placed it higher; and by 

 using that number in connection with the results found before we 

 get the following summary: 



Table XII. — Relative value of early and late sprayings in 190Jf. 



Value of early sprayings : 



Worms killed in first brood 220 



Worms killed in second brood 470 



Worms killed in first brood would have increased to 1, 100 



Total value of early sprayings 1. 796 



Value of late sprayings : 



Worms killed when applied alone 579 



Worms killed when following early ones 305 



Total value of late sprayings either 579 or 305. 



This comparison shows that the early sprayings have a protecting 

 power over three times as great as that of the late ones when applied 

 alone and under the most favorable conditions, and almost six times 

 as great as the late sprayings when following the early ones. Still it 

 does not bring out the full value of the early sprayings in comparison 

 with the late ones, as the results in the following year will show. 



Table XIII. — Relative value of earh) and late sprayings in 1905. 



Value of early sprayings : 



Worms killed in first brood 01 



Worms killed in second brood 209 



Worms prevented in second brood 455 



Total value of early sprayings 75.", 



Value of late sprayings : 



Worms killed when following early ones 45 



Total value of late sprayings 45 



Here Ave see that the eifect of the early sprayings in 1904 was cumu- 

 lative and resulted in a marked decrease in the number of worms 

 appearing the following year. As a result, the early sprayings de- 

 stroyed so large a percentage of the worms that there was a striking 

 decrease in the number of worms killed by the late sprayings and a 

 corresponding decrease in the comparative value of the late spraying- 

 as compared with the early ones. 



Comparing the results of two years we find that the late sprayings 

 which followed the early ones killed one worm to the early ones' six 

 the first year and only one to the early ones' 1(> the second year. 1>\ 

 the third year the worms were so reduced in numbers that no late 

 sprayings were applied. 



7487— No. 07— 07 5 



