100 n 



% 



PCs 



CAPTURED 



80 

 60 

 40 

 20-1 

 



■ small (M.9) 

 n medium (M. 26) 

 D large (M.7) 



■ nl^^ 



Perimeter 

 row 



12 



22 



32 



42 



DISTANCE (in yards) 



Figure 2. Distribution of overwintered PCs that penetrated into commercial orchard blocks according 

 to tree size and distance (from perimeter-row trees) at which Circle traps were deployed (20 traps per 

 orchard block). 



May 23-24, just after the petal fall spray of insecticide 

 against PC. Thus, results show captures that occurred 

 during a two-week period. 



Results 



Figure 2 reveals that extent of PC penetration into 

 commercial orchard blocks varied considerably 

 according to tree size. For blocks having large and 

 medium trees, most PCs were captured by Circle traps 

 located on perimeter-row trees (about 70 and 67%, 

 respectively). For blocks having small trees, most PCs 

 (about 78%) penetrated into interior rows. 



Conclusions 



Based on our findings, we conclude that by petal 

 fall: (1) most PCs were congregated on perimeter-row 

 trees in blocks of large or medium-sized trees (M.7 or 

 M.26 rootstock), and (2) a substantial number of PCs 

 was able to penetrate inside blocks (at least up to 42 



yards in our study) where trees were small (M.9 

 rootstock). An alternative explanation is that PCs may 

 have overwintered within rather than penetrated into 

 interiors of some blocks. Our results here, when 

 combined with findings reported in the preceding article, 

 may explain why growers who might limit all insecticide 

 application against PC exclusively to peripheral-row 

 trees would attain unacceptable PC control. We aim to 

 repeat this study in 2004 to corroborate our findings 

 here. 



A ckn o wledgm en ts 



We are grateful to Keith Arsenault, Gerry Beime, 

 Bill Broderick, Aaron Clark, Don Green, Tony Lincoln, 

 Joe Sincuk, and Steve Ware for permitting use of 

 orchards for this study. This work was supported by 

 funds from a USDA Northeast Regional IPM grant, a 

 USDA Northeast Regional SARE grant, a Hatch grant, 

 and a USDA Crops at Risk grant. 



%X^ %1> %1> «i^ vi# 

 ^j^ ^j^ ^j^ #^ #Y* 



Fruit Notes, Volume 69, Winter, 2004 



