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Figure 1. Unsprayed section of the apple orchard used for this study (UMass Cold Spring Orchard; 

 Belchertovvn, MA). Panel and pyramid traps were deployed in pairs along the periphery of the orchard block, 

 in close proximity to woods, the main overwintering sites of adult PCs. The perimeter of the block was about 

 500 yards. Picture: courtesy of Jon Clements (UMass Extension). 



the orchard. The predominant bait used for luring PCs 

 to traps was composed of benzaldehyde (attractive, 

 synthetic, host-plant odor) in association with and 

 grandisoic acid (PC aggregation pheromone). For each 

 trapping year, trap deployment and baiting took place 

 approximately during the silver-tip stage of bud 

 development. Traps were inspected for PC captures on 

 a daily basis (7:30-10:00 AM) from the moment of trap 

 deployment until fruit reached 1 .2 inches in diameter 

 (by late June/early July). All adult PCs captured were 

 brought to the laboratory, where they were sexed. All 

 females captured were dissected under a 

 stereomicroscope to determine the sexual maturity 

 stage (presence of mature eggs) and mating status 

 (presence of sperm in the spermatheca). 



Characterizing PC immigration. The process of 

 PC immigration into the apple orchard was 



characterized beginning with the day of first captures 

 by traps. The next important stages of PC immigration 

 were the 50"" and 80* percentiles of cumulative 

 captures. The latter occurred around petal fall, the stage 

 of tree phenology at which PCs have shown the highest 

 activity and dispersal and the time at which the first 

 insecticide is commonly applied against PC. We ended 

 the studies by late June/early July, when no captures 

 occurred for 3-4 consecutive days with relatively high 

 temperatures. 



Classification of tree phenology. We monitored 

 and characterized, on a daily basis, the different stages 

 of bud and fruit development on the Mcintosh trees 

 using the following numerical code: (1) silver tip, (2) 

 green tip, (3) half-inch tip, (4) tight cluster, (5) first 

 pink, (6) full pmk, (7) first bloom, (8) full bloom, (9) 

 petal fall, (10) within a week after petal fall, and (11) 



Fruit Notes, Volume 69, Fall, 2004 



