averaged across both types of trapped plots and grower- 

 sprayed plots, interior monitoring traps in susceptible 

 cultivars captured substantially more ( 1 30% more) wild 

 AMF than in tolerant cultivars. The ratio of front-row- 

 trap/interior-row-trap captures in blend and BH plots 

 was the same within each cultivar type as it was for 

 both cultivars together (about 7: 1 for blend and about 

 5:1 forBH). 



Effects of adjacent habitat in 2000 and 2001. In 

 2000, of the total number of AMF captured by all traps 

 in all orchards, 41% were captured in blocks adjacent 

 to woods (Figure 3). A similar percentage (37%)) was 

 captured in blocks bordering hedgerows. The smallest 

 percentage of total captured flies was found in blocks 

 bordering open fields (21%). 



In 2001, blocks bordering hedgerows had the 

 highest percentage (47%) of total fly captures, followed 

 by orchard blocks bordering woods (32%), and blocks 

 that were adjacent to open fields (21%)) (Figure 3). 



Conclusions 



In 2000, in the same orchards studied in 200 1 , data 

 suggested that there was virtually no difference in AMF 

 penetration into orchard blocks when front-row traps 

 baited with the five-compound blend were placed either 

 1 m or 5 m apart. In 200 1 (with front-row traps spaced 



10 m apart), front-row traps in blend plots captured 

 more flies than front-row traps in BH plots. Although 

 there was little difference in the mean number of wild 

 AMF that penetrated into the interior of the two baited 

 plots, the ratio of front-row to interior-row-trap captures 

 was higher when front-row traps were baited with 

 blend. Inasmuch as blend appears to be more capable 

 than BH of drawing AMF to the vicinity of traps (based 

 on front-row-trap captures), these data suggest that 

 blend odor-bait is better than BH in preventing AMF 

 from penetrating into the interior of orchards. 



Orchard blocks with tolerant front-row cultivars 

 experienced substantially more AMF captures on front- 

 row traps baited with blend than BH. The difference 

 was much less for blocks with susceptible front-row 

 cultivars. This suggests that baiting front-row traps 

 with blend in tolerant cultivars attracts many more flies 

 than baiting tolerant trees with BH. In both 2000 and 

 200 1 , and in trapped as well as grower-sprayed plots, 

 more total AMF were captured in orchard blocks with 

 susceptible front-row cultivars than in those with 

 tolerant front-row cultivars. However, the ratio of 

 front-row to interior-row-trap captures remained the 

 same regardless of cultivar. This suggests that each 

 odor bait is just as effective in one cultivar type as it is 

 in the other cultivar type in preventing AMF penetration 

 into the orchard interior. 



Percent of Total AMF Captures 

 2000 2001 



woods 

 42% 



Figure 3. In 2000 and 2001, across all blocks, all traps, and all sample 

 periods, percentage of the total AMF captures according to adjacent habitat 

 (woods, hedgerow, or open field). For the purpose of this figure, all 12 

 orchard blocks were considered in 200 1 . 



Fruit Notes, Volume 67, Spring, 2002 



23 



