CONTROL OF CODLING MOTH IN ARID REGIONS. 65 



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

 using that number in connection with the results found before avc 

 get the following summary : 



Table XII. — Itchitive value of vurlij utid lute .sitruyimjs in IDO't. 



Value of CMi'ly s]ii-;i.viii.i:s : 



Worms killed in first brood 220 



AVoriiis kill(>d in second brood 47G 



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



Total value of early sprayings 1,790 



Value of late sprayings: 



Worms killed when applied alone 579 



Worms killed when following early ones 305 



Total valu(> of late sprayings either 570 or 305. 



This comparison shows that the early sprayings have a protecting 

 j^ower 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 spra^nngs in comparison 

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



Table XIII. — I'chitirr raliic of rarh/ ainl hitr sj)r(iifiinjs in J!JO'>. 



Value of early sprayings : 



Worms killed in first brood 91 



Worms killed in second brood 209 



Worms prevented in second brood 455 



Total value of early sprayings 7,55 



Value of late sprayings: 



Worms killed when following early ones 45 



Total value of late si»rayings 45 



Here we see that the etl'ect of the early sprayings in l!)0-t was cumu- 

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

 ap])earing the foHowing year. As a result, the early sprayings de- 

 stroyed so large a i)ei-centage of the worms that there was a striking 

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

 corresj)()nding decrease in the com])arative value of the late sprayings 

 as compared with the early ones. 



Comparing the results of two years we find that the late sj^rayings 

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

 the tirst 3'ear and only one to the early ones' KI the second year. By 

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

 sprajdngs were applied. 



7487— No. 07—07 5 



