Tabic 2 I'lc'ld response indices (KIsj ol plum cuiciilio adulls lo (iilor cumpouruls :il conccnlralions ol 5 "/< . anil 

 ().5'/f in mineral oil. 



Compound 



Experiment 

 (5%) 



Expcrimcnl 2 



5% 



0.5% 



80* 



25 



50 



20 



100* 



26 



Significantly different from zero at odds of 19 to 1. 



0.1%. At 0.01%, ethyl isovalerate and limonene re- 

 sulted in positive and significant RIs, and all others re- 

 sulted in nonsignficant RIs. 



Field Results. In the first field experiment, the 

 only significant RIs were recorded for 5% solutions of 

 ethyl isovalerate and limonene (Table 2). In a second 

 set of experiments testing ethyl isovalerate and limonene 

 (the most attractive compounds from the first field ex- 

 periment) and 3-hexanol (the least attractive compound 

 from the first field experiment), significant RIs were 

 recorded for 5% solutions of ethyl isovalerate and li- 

 monene, but not 3-hexanol at 5% or any of the three at 

 0.5% (Table 2). 



Conclusions 



Data obtained from our laboratory and field ex- 



periments are in agreement. Two compounds, ethyl 

 isovalerate and limonene, proved significantly attrac- 

 tive to PCs under the test conditions described here. 

 For the future, we plan lo test these two attractive com- 

 pounds alone or in combination with male-produced 

 pheromone as baits for the pyramid traps described in 

 1997 and 1998 Winter Issues of Fruit Notes, and also 

 for alternative trap designs including a circle trap and a 

 twig-mimicking black cylinder trap to see if trap effi- 

 cacy is increased, 



A ckn ow ledge m ents 



This work was supported by USDA Hatch funds 

 and by the New England Tree Fruit Growers Research 

 Committee. We thank Jim Hardigg for allowing us to 

 use his orchard for part of this work. 



vt* vl> *!>* vl>* vT>* 

 y^ *^ *^ #^ #^ 



Fruit Notes, Volume 63 (Number 3), Summer, 1998 



17 



