Golden Delicious. The early ripening cultivar Paula 

 Red and the mid-ripening cultivars Mcintosh and 

 Cortland always ranked among the bottom six cultivars 

 in terms of preference. 



Discussion 



Traps on early cultivars, with the exception of 

 Paula Red, accumulated substantial numbers of AMF 

 dunng the early and/or mid period of the AMF season. 

 Preference among early cultivars appeared to shift 

 depending on ripening stage and the onset of fruit drop 

 or harvest. For mid-ripening cultivars, traps on Gala 

 accumulated relatively high numbers of AMF in most 

 years and in most orchards early in the season, 

 maintained their high preference rank across mid 

 season, and reached their peak late in the season. With 

 the exception of trees of a specific strain (Rogers Red 

 Mcintosh), and trees at one locale in one year 

 (Cortland), traps on Mcintosh and Cortland 

 accumulated few AMF. Among late-ripening cultivars, 

 traps on Fuji trees accumulated large numbers of flies 



dunng mid and late season. Both Delicious and Golden 

 Delicious accumulated moderate numbers of AMF 

 early in the season. By late season, these two late- 

 ripening cultivars, along with Braebum, reached a 

 comparatively high rank. 



Cultivar composition strongly influenced AMF 

 distribution in orchards in our study. Contrary to earlier 

 findings (Murphy et al., 1991), we found that AMF 

 preference for some apple cultivars is not governed 

 exclusively by the time of fruit ripening but rather by 

 specific properties of fruit, possibly odor composition. 

 Indeed, in some cases more than 80% of total AMF 

 captures in a trapping period occurred on traps placed 

 on trees of a single mid-npening and a single late- 

 ripening cultivar (Gala and Fuji). Moreover, AMF 

 accumulated in considerable numbers on traps on Fuji 

 trees in mid-season, despite the fact that those trees 

 bore relatively unripe green fruit at that time. Findings 

 here, in combination with findings on AMF oviposition 

 preferences among cultivars (see following article), 

 could have a substantial influence on success of using 

 odor-baited traps to control AMF. 



20 



Fruit Notes, Volume 66, 2001 



