CODLING MOTH IN SANTA CLARA VALLEY. 171 



tions for that year. Theoretically, on account of the very cold season 

 there should have been a large first brood and a small second brood, 

 which is further borne out by the small percentage of transforming 

 larvae of the total band collection. One fact is evident, however, 

 there were more codling-moth larvae present in the field in 1909 and 

 1910, which gave a larger series in the band records for these years 

 in comparison with 1911. 



The 1911 season was apparently so cold early that moths did not 

 oviposit properly and the temperature conditions probably exerted 

 such an influence that the infestation was light, therefore cutting 

 down both broods and making them nearly equal. 



CONTROL OF THE CODLING MOTH ON PEARS AND APPLES IN 

 THE SANTA CLARA VALLEY. 



While prunes, apricots, and cherries are the chief fruits raised in 

 this valley, there are about 500 acres set to apples and 1,400 acres 

 to pears. These orchards on the whole have probably paid better 

 financially the past five years than many orchards of the first three 

 varieties of fruits. Situated* as they are, on the lower and wet but 

 rich soils near Alviso, they have escaped the attacks of the chief 

 insect pest to deciduous fruits in central California, the pear thrips 

 (Euthrips pyri Daniel). The codling moth, aside from several species 

 of plant-lice, has been practically the only insect worthy of the atten- 

 tion of apple and pear growers in the Santa Clara Valley. 



It is needless to say that spraying, both good and bad, has been 

 practiced for the codling moth, but the majority of the fruit growers 

 have either sprayed at the wrong time or in an indifferent manner 

 or have used ineffective poisons. 



The writers have seen apple orchards that had been sprayed three 

 times during the season and these had from 75 to 80 per cent wormy 

 fruit. Until the past two or three years there was a tendency to 

 do slipshod work at low pressure, and even now many growers try 

 to use too many leads of hose and to cover more trees with too little 

 material. The practice of using four lines of hose on one spray 

 outfit should be discouraged since it is difficult to maintain a suffi- 

 ciently high pressure and the nozzle men frequently interfere with 

 one another. It would be much better business to use more spray 

 outfits, and even to spray from a tower. 



Data are presented here from one apple orchard and one pear- 

 orchard where the spraying was done after the directions of this 

 bureau. On both orchards the work was in the nature of a commer- 

 cial demonstration and it is in a way unfortunate that no checks 

 could be obtained on the pear orchard, which was sprayed two suc- 

 cessive years, although the early history of the place is known. 

 56602°— Bull. 115, pt. 3—13 5 



