Diseases and Pests of the Apple and Their Control 207 



through the skin made by the worms before they succumb 

 to the poison. 



The seriousness of this insect is somewhat variable from 

 season to season and in different fruit-growing districts. 

 In the eastern states the codlin-moth can be controlled by 

 one to three thorough spray applications. In the Middle 

 West and in the arid fruit-growing regions of the West, ' 

 the insect is more difficult to control, often requiring six 

 to seven sprays. It thrives especially under the warm 

 dry climatic conditions of the West, whereas its develop* 

 ment in the East is retarded by the occurrence of rains and 

 periods of cool weather. The number of broods is in- 

 fluenced by weather conditions as indicated by the fact 

 that there are four broods in the Pecos Valley of New 

 Mexico while in Maine there is practically but one, the 

 second brood being very small. 



The codlin-moth passes the winter in the worm or 

 larval stage, within a small silken cocoon which is nor- 

 mally spun beneath the loose bark of the trunk. By the 

 time the apples are in bloom, many of the worms have 

 changed to the pupal state, after which they further trans- 

 form and issue as moths. The eggs are deposited on the 

 leaves and sometimes on the fruit itself. The worms 

 hatch usually in six to ten days, depending on the weather, 

 and soon eat their way into the fruit if it is not properly 

 protected by poison. 



Before proper control measures can be applied, it is 

 essential to know the life history of the codlin-moth. It 

 is important to have information on the number of broods 

 and the time when each brood is hatching in maximum 

 numbers. It will, therefore, be readily appreciated that 

 no one spraying schedule will be applicable in all fruit- 



