captures of PCs across the season and total amount of fmit 

 mjury (at season's end) for pyramid traps baited with ben- 

 zaldehyde or limonene and for Circle traps baited with li- 

 monene (Table 1 ). 



When effects of orchard architecture and outlying habitat 

 are considered, results show that trap captures were about 

 three times greater and fruit injury was about four times 

 greater when Gala, Jonagold or Fuji trees comprised perim- 

 eter rows than when Mcintosh or Empire trees comprised 

 perimeter rows (Table 2). Also, we were surprised to find 

 that trap captures and fruit injury on perimeter rows directly 

 facing 100 or more yards of open space were nearly as great 

 as on perimeter rows directly facing woods 10 yards or less 

 away (Table 2). 



Conclusions 



Our findings indicate that PCs discriminate quite well 

 between cylinder traps or Circle traps baited with benzalde- 

 hyde, ethyl isovalerate or limonene (each in combination 

 with grandisoic acid) and corresponding unbailed traps. This 

 is the first time anywhere that PCs have been found to re- 

 spond in a substantial way to odor-baited traps placed in 

 apple tree canopies. These results will ser\e as a spring- 

 board for future studies aimed at pinpointing the dose at 

 which each of these three synthetic fruit volatile compounds 

 is most attractive in association with cylinder or Circle traps. 

 PCs did not discriminate as well between pyramid traps 

 baited with these three compounds (in combination with 

 grandisoic acid) and corresponding unbailed pyramid traps. 

 Perhaps the location of the odor bait (at the top of a pyramid 

 trap) was too far away from the point of PC entry (usually at 



the base of a pyramid trap) to be attractive, or perhaps the 

 strong visual stimulus of a pyramid trap exceeded the stimu- 

 lus of attractive odor 



Despite the progress in trapping PCs in commercial or- 

 chards reported here, we have not yet reached our goal of 

 development of an odor-baited trap whose captures reflect 

 both the timing and the amount of PC injury to fruit. Even 

 so, the findings reported here represent progress toward this 

 goal. 



Finally, we were surprised by the much greater number 

 of PC captures and amount of injury on perimeter Gala, 

 Jonagold, and Fuji trees compared with perimeter Mcintosh 

 and Empire trees. We were also surprised by the large aver- 

 age amount of captures and injuries on perimeter trees fac- 

 ing open fields. Perhaps PCs are immigrating into orchards 

 from distances much further than we have recognized, and 

 doing so especially in response to odor emitted from certain 

 attractive cultivars. We plan to explore both of these as- 

 pects further in the coming year 



A cknowledgem en ts 



We are grateful to the following growers for participat- 

 ing in this study: Keith Arsenault, Gerry Bierni, Bill 

 Broderick, Dave Chandler, Tom Clark, Don Green, Tony 

 Lincoln, Joe Sincuk, Maurice Tougas, and Steve Ware. This 

 work was supported by Massachusetts State Integrated Pest 

 Management Funds, Northeast Regional Competitive Inte- 

 grated Pest Management Funds, Northeast Sustainable Re- 

 search and Education grant funds, the Massachusetts Soci- 

 ety for Promoting Agriculture, and the New England Tree 

 Fruit Growers Research Committee. 



it it it it it 



Fruit Notes, Volume 65, 2000 



35 



