CONCLUSIONS 



The use of a vapor generator with dichlorvos would require less manpower than 

 that for the daily thermal aerosol treatments. But the method loses some of its 

 automatic advantages since it has to be adjusted periodically to control the dichlorvos 

 output. To maintain effectiveness, it would still be necessary to increase the daily 

 operating time as the season progresses. The increase necessary could be 

 determined by visual observations or by the use of traps. 



Since the automatic features of the vapor generator are among the most 

 important characteristics of the machine, to set the machine to operate on a daily 

 basis would be more desirable. Applications of dichlorvos at daily intervals were 

 more effective against drosophila than less frequent applications, except when low 

 concentrations were being produced by the generator. One filling of the chamber with 

 30 pounds of pellets does not seem to be sufficient for the entire grape crushing 

 season in a cellar of this size. 



Since this m-achine was tested, the vapor generator has been remodeled. 

 Preliminary tests made with the new machine indicate that its performance will be 

 very similar to that of the old machine under conditions like those in this experiment. 



10 



