Even so, captures of AMF on four interior 

 unbaited red spheres per block were almost 50% 

 lower in second-level blocks baited with the two 

 types of odor than in nearby first-level blocks. 

 AMF injury in these three second-level blocks 

 was similar to nearby blocks. The very large 

 number of AMF caught on interception traps 

 coupled with the excellent degree of AMF control 

 obtained in blocks trapped with both synthetic 

 food and fruit odor suggests that this double- 

 odor trapping procedure may be very effective 

 for large (six to nine acres) blocks. We need, 

 however, to improve upon the type and distribu- 

 tion method of the synthetic food odor. 



Fruit injury by codling (CM) moth averaged 

 less than 0. 1% in all block types, indicating that 

 CM injury did not increase in second-level blocks 

 where host trees within 100 yards of the block 

 perimeter were removed as a substitute for 

 summer insecticide use against this important 

 pest (Table 4). Leafroller (LR) injury averaged 

 0.2% in both full second-level blocks and nearby 

 first-level blocks. We will continue to monitor 

 carefully for leafroller because of concern that 

 leafroller populations may grow in blocks in 

 which the interior is not sprayed throughout the 



summer. No lesser appleworm injury was found 

 on any sampled fruit. 



The effects of removing drops from the or- 

 chard on populations of AMF, CM, and lesser 

 appleworm of removing drops from the orchard 

 will not be apparent until next year; however, 

 our experience with first-level, second-stage 

 IPM from 1987-1990 suggests that a no-spray 

 approach after early June may not succeed 

 unless all integrated management techniques 

 are adopted. We continue to believe that re- 

 moval of drops is an essential component of 

 second-level IPM. 



Fewer dosage equivalents of pesticide were 

 applied against summer fruit pests in second- 

 level blocks than in first-level blocks (0.3 vs. 1 .0), 

 but pesticide use was also low in first-level 

 blocks (Table 2). This may be explained by the 

 use of low rates of Guthion™ and the use of 

 monitoring traps. In one case the threshold for 

 treatment of AMF was never reached and no 

 mid-season insecticide was applied in the first- 

 level block (Table 3). 



Foliar Pests and Predators. The second- 

 level approach of allowing natural enemies to 

 build in the absence of insecticide use after early 



8 



Fruit Notes, Spring, 1992 



