attracted to males alone and synthetic grandisoic acid 

 alone in significantly greater numbers than to controls, 

 these responses were quickly lost when host fruit odor 

 was included. Both males and females were equally 

 attracted to odors of males feeding on plums and syn- 

 thetic grandisoic acid held with plums when compared 

 to plums alone, indicating that attraction to host fruit 

 odor was not enhanced by the presence of male-pro- 

 duced or synthetic pheromonal odor. However, syn- 

 thetic grandisoic acid impregnated into rubber septa 

 may not have been very attractive due to chemical bind- 

 ing to septa but could be more attractive if formulated 

 differently. In general, our studies revealed that fruit- 



based odors are the most attractive to PCs and that only 

 minor contributions are made by addition of conspe- 

 cific odors or grandisoic acid. Therefore, we conclude 

 that attractive fruit-based volatiles should be the main 

 additive to an attractive visual trap to create a success- 

 ful monitoring system for PCs. 



Acknowledgments 



This work was supported by Hatch funds and by 

 the New England Tree Fruit Growers Research Com- 

 mittee. 



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Fruit Notes, Volume 64 (Number 3), Summer, 1999 



