Summer Fruit-injuring Pests. Every 

 three weeks after early June, perimeter row 

 apple trees in transitional second-level blocks 

 were treated with insecticide to control AMF. 

 The block interior remained free of insecticide 

 after early June. AMF injury averaged 0.3% in 

 both the transitional second-level blocks and the 

 nearby first-level blocks (Table 3). AMF cap- 

 tures on interior monitoring traps indicated that 

 in most cases few AMF penetrated into the 

 orchard interior. In one second-level block, 

 however, trap captures in early August sug- 

 gested that AMF penetration warranted a full 

 block spray, which was applied August 8. 



Unmanaged apple and pear trees were re- 

 moved from within 100 yards of the six transi- 

 tional second-level blocks and, as in the full 

 second-level blocks, codling moth injury aver- 

 aged less than 0.1% in both transitional second- 

 level blocks and nearby first-level blocks. 

 Leafroller injury was slightly, but not signifi- 

 cantly, higher in the transitional second-level 

 blocks than in the first-level blocks (0.2% vs. 

 <0.1%). Growers applied about three times as 

 much insecticide against mid-season fruit pests 

 in first-level blocks as in transitional second 

 level blocks (1.6 vs. 0.5 dosage equivalents) 

 (Table 2). 



Foliar Pests and Predators. In the tran- 

 sitional second-level blocks, average numbers of 

 pest and predatory mites were present in ratios 

 indicating that adequate control was likely dur- 

 ing much of July and August (Table 5). In each 

 case, however, predatory mites were present in 

 high numbers in only one of the six transitional 

 blocks. In several blocks, miticides were recom- 

 mended and applied in order to avoid a mite 

 outbreak (Table 2). 



Both white apple and potato leafhopper in- 

 festation levels on terminals and white apple 

 leafhopper injury to fruit averaged slightly but 

 not significantly higher in transitional second- 

 level blocks than in nearby first-level blocks 

 (Table 6). 



All six transitional second-level blocks were 

 treated with Dimilin™ against second genera- 

 tion leafminers. The season-long average num- 

 ber of leafmines on 100 leaves was 39 in second- 



level blocks and 65 in first-level blocks. 



Green apple aphids infested an average of 

 48% of terminals in transitional second-level 

 blocks and 38% of terminals in nearby first-level 

 blocks in July. Predators were found on an 

 average of 30% of terminals in transitional sec- 

 ond-level blocks and 18% of terminals in first- 

 level blocks. Although levels of green apple 

 aphids were slightly higher in second-level 

 blocks than in first-level blocks, higher levels of 

 predation indicated adequate biocontrol of 

 aphids. Similar percentages of terminals in the 

 transitional second-level blocks and in first- 

 level blocks were infested with wooly apple 

 aphids (14% and 18%, respectively). None of the 

 differences in aphid population levels were sta- 

 tistically significant. 



Spider monitoring in the transitional sec- 

 ond-level blocks indicated that by late summer 

 the numbers of spiders in the second-level block 

 were significantly higher than the numbers in 

 the nearby first-level block (Table 7). In mid 

 June, an average of about two spiders was 

 captured in both types of block, but by late 

 August there were an average of 20 spiders 

 captured in second-level blocks and only two in 

 first level blocks. Insecticide and miticide use in 

 first-level blocks near transitional second-level 

 blocks was higher than in any other type of 

 block, and this may explain the low number of 

 spiders found in these blocks. 



A significantly greater number of dosage 

 equivalents of pesticide was applied in first level 

 blocks than in second-level blocks (8.7 vs. 6.5) 

 (Table 2). 



Conclusions 



In conclusion, we generally are pleased with 

 our first year trials of second-level IPM manage- 

 ment practices for insects and mites. Despite 

 the increase in block size from two to three acres 

 under first-level, second-stage IPM to six to nine 

 acres under second-level IPM, control of AMF 

 through both interception traps and perimeter 

 row spraying was generally successful. The 

 addition of ammonium carbonate as a food odor 

 bait shows promise for future AMF interception 

 trap strategies. Early season injury from plum 



12 



Fruit Notes, Spring, 1992 



