Summer Fruit-injuring Pests: 

 Full Second-level IPM 



Odor-baited sticky red spheres were hung 

 every five yards on perimeter apple trees of each 

 full second-level experimental block to intercept 

 immigrating AMF. These were baited with both 

 butyl hexanoate, a synthetic fi-uit odor deployed 

 in polyethylene vials, and ammonivun acetate, a 

 sjTithetic food odor released through a Consep™ 

 membrane. 



Interception trap captures averaged 2430 in 

 the six full second-level blocks, indicating that 

 AMF pressure was moderate in 1992. In 1991, 

 trap captures averaged 3562 in three blocks in 

 which traps were baited with both food and firuit 

 odor. Captures ofAMF on four interior unbEii ted 

 monitoring traps (indicative of AMF penetra- 

 tion into the block interior) were statistically 

 similar in second-level blocks and in nearby 

 first-level blocks. AMF injury to firuit at harvest 

 in second-level blocks was similar to that in 

 nearby first-level blocks (Table 3). One second- 

 level block, however, had 8% injury to Cortlands 

 in mid-September. The nearby first-level block 

 had no Cortlands , and all the Mcintosh had been 

 picked, so no comparison was available. 



The second year of use of both butyl 

 hexanoate and ammonivim acetate (or carbon- 

 ate) to bait the AMF interception traps indicates 

 that this double-odor strategy may be very effec- 

 tive in large blocks. We ehminated the problem 

 of quick loss of ammonia by replacing polyethyl- 

 ene vials with slow release membranes. Tests 

 performed in our laboratory showed that flies 

 continue to be attracted to these membranes 

 even afler they have been in the field for several 

 months. Tests also indicated, however, that 

 fewer flies approached the trap if the membrane 

 flapped loosely in the wind. In addition, traps 

 may require more fi-equent cleaning than we 

 had previously thought, especially if the double- 

 odor trapping procedure results in the capture of 

 additional non-target insects. In 1992, we 

 cleaned our traps once a month, but in one 

 orchard, trap captures during a one-month pe- 

 riod were 271% higher on traps which were 

 cleaned of all insects than on those which were 

 not cleaned thoroughly, indicating that as in- 



sects build up on the traps, trap captures de- 

 crease. In high-pressure situations, more fre- 

 quent trap cleaning may be necessary if AMF 

 are to be captured effectively. 



Fruit injury by CM averaged less than 0.1% 

 in both block types for the second year. 

 LeafroUer (LR) injury averaged 0.2% in fuU 

 second-level blocks for the second year, and was 

 0.1% in nearby first-level blocks (Table 4). We 

 will continue to monitor carefiilly for leafrollers 

 because of concern that leafi-oller populations 

 may grow in blocks in which the interior is not 

 sprayed afler early or mid-June. No LAW or San 

 Jose scale (SJS) injury was found (Table 4). 



No insecticides were apphed in second-level 

 blocks after mid-Jime. In the companion first- 

 level blocks, growers applied an average of 2.0 

 dosage equivalents of pesticide after mid-June, 

 and sprayed the block an average of 2.2 times 

 (Table 2). 



Summer Fruit-injuring Pests: 

 Transitional Second-level IPM 



Every three weeks after early June, i)erim- 

 eter row apple trees in transitional second-level 

 blocks were treated with insecticide to control 

 AMF. The block interior remained firee of insec- 

 ticide after early June. AMF injury averaged 

 0.2% in transitional second-level blocks and 

 0.1% in the nearby first-level blocks, slightly 

 lower in both cases than in 1991. On average, 

 3.5 AMF were captured on unbaited interior 

 monitoring traps in transitional second-level 

 blocks and 3.7 in first-level blocks, indicating 

 that in most cases relatively few AMF pen- 

 etrated into the orchard interior (Table 3). In- 

 secticide use after mid- June was reduced signifi- 

 cantly in transitional second-level blocks com- 

 pared to first-level blocks because apphcations 

 were made only to the block perimeter. Total 

 dosage equivalents of insecticide applied 

 against fi-uit pests afler mid-June averaged 0.7 

 in transitional second-level blocks and 3.1 in 

 first-level blocks. Growers also sprayed transi- 

 tional second-level blocks slightly less fre- 

 quently (Table 2). 



Unmanaged apple and pear trees were re- 

 moved fi"om within 100 yards of the six transi- 



Fruit Notes, Winter, 1993 



27 



