traps of the same type, and captured twice as many 

 PCs as traps baited with GA alone (Figure 2A). Panel 

 traps baited with GA alone captured more PCs than 

 panel traps baited with BEN alone or unbaited traps. 

 Pyramid traps baited with BEN+GA captured 5 times 

 more PCs than unbaited pyramid traps and 2.5 times 

 more PCs than pyramid traps baited with GA alone. 

 Pyramid traps baited with BEN alone or GA alone 

 captured more PCs than unbaited pyramid traps (Figure 

 2B). 



For both trap types, the presence of EFV or LIM 

 did not enhance the attractiveness of GA to PCs (Figure 

 2A and B). Also, for both trap types, consistently more 

 PCs were captured by traps baited with GA alone than 

 by traps baited with EfV alone, LIM alone, or unbaited 

 traps. In no case did EIV or LIM alone significantly 

 enhance adult response above that to control traps. 



2002 Study. In all, 1,305 PCs were captured by 

 traps (662 PCs by panels and 643 PCs by pyramids) 

 over the period of 82 days that comprised the PC season 

 in 2002 (April 17 -July 8). 



Figure 3A shows PC captures by panel traps 

 according to amounts of BEN and GA evaluated. 

 Overall, panel traps baited with the high release rate 

 of GA captured about 35% more PCs than panel traps 

 baited with the low release rate of GA. When we 

 examined PC captures by panel traps baited with the 

 low release rate of GA, we found a significant positive 

 linear relationship between the amount of BEN and 

 the extent of captures. As depicted in Figure 3A, 

 increases in the amount of BEN released corresponded 

 to increases in captures by panel traps, with the 

 maximum number of PCs captured corresponding to 

 the high release rate of BEN (40 mg/day). For panel 

 traps baited with the high release rate of GA, we found 

 that the most attractive release rate of BEN was again 

 40 mg/day, although differences among BEN 

 treatments were only numerical. 



Figure 3B presents PC captures by pyramid traps 

 according to amounts of BEN and GA used. Pyramid 

 traps captured similar numbers of PCs regardless of 

 the amount of GA used. For pyramid traps baited with 



the low release rate of GA, we found that the mere 

 addition of BEN, regardless of the dose, enhanced PC 

 captures relative to traps baited with GA alone (Figure 

 3B). For pyramid traps baited with the high release 

 rate of GA, we found an increase in captures as the 

 amount of BEN released increased but only up to a 

 maximum of 10 mg/day. Beyond that amount, BEN 

 did not enhance, but rather decreased the attractiveness 

 ofGA. 



Conclusions 



Our results from the 2001 study indicate that, 

 among all odor combinations evaluated, BEN in 

 association with GA was the most attractive bait for 

 PCs. Results from the 2002 study, as well as an 

 assessment of cost of both BEN (as formulated by us) 

 and GA (obtained from Great Lakes EPM), indicate that 

 a high release rate of BEN (40 mg/day/trap) in 

 association with a low release rate of GA (1 mg/day/ 

 trap) seems to be the most cost-effective bait 

 combination to be used for panel as well as pyramid 

 traps. With our approach, BEN provided sustained 

 attractiveness to PCs across the entire period of 

 immigration (82 days in 2002). Placement of BEN- 

 releasing vials outside of trap tops (for pyramid traps) 

 appeared to preclude the kind of close-range repellency 

 found in previous studies in which BEN-releasing vials 

 had been positioned inside the tops of pyramid, Circle, 

 or cylinder traps. 



We conclude that BEN (at 40 mg/day of release) 

 in association with GA (at 1 mg/day of release) 

 constitutes a powerful lure that may greatly improve 

 the effectiveness of monitoring traps for PC. 



A cknowledgm ents 



We thank Phillip McGowan for assistance. This 

 study was supported with funds provided by a USDA 

 Northeast Regional IPM grant, a Hatch grant, the New 

 England Tree Fruit Research Committee, and the 

 UMass HRC Trust Fund. 



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Fruit Notes, Volume 67, Fall, 2002 



17 



