Effect of Distance Between Traps on 

 Interception of Apple Maggot Flies on 

 Perimeter Apple Trees 



Margaret M. Christie, Ronald J. Prokopy, James Gamble, 



David Heckscher, and Jennifer Mason 



Department of Entomology, University of Massachusetts 



Second-stage IPM methods for arthropod pest 

 control in apple orchards, in which no insecticide or 

 miticide is applied after the final plum curculio 

 spray, rely on use of sticky red traps to control apple 

 maggot flies (AMF). We previously reported on 

 three years of trials (1987-89) of second-stage IPM 

 methods in Massachusetts orchards [Fruit Notes 

 55(l):4-9]. In 1990, we evaluated slightly altered 

 approaches when employing traps to intercept 

 immigrating apple maggot flies. The results of these 

 trials in 10 apple orchard blocks are presented here. 



In 1987, we began working in 2 blocks in each of 

 6 Massachusetts orchards. Each grower used sec- 

 ond-stage IPM methods in one block of 2 to 3 acres 



and first-stage IPM methods in another block. In 

 late June, apple maggot traps were hung 10 yards 

 apart on perimeter apple trees of each second-stage 

 IPM block. One vial of butyl hexanoate, a synthetic 

 apple volatile, was placed near each trap. In Septem- 

 ber, we sampled 500 fruit in each block and found 

 that 1.6% of the fruit in the second-stage blocks and 

 0.4% in the first-stage blocks had AMF injury (Table 

 1). 



In 1988 and 1989, we hung apple maggot traps 5 

 yards apart in perimeter row apple trees. Again, one 

 vial of butyl hexanoate was positioned near each 

 trap. Each year, we sampled 200 fruit per block in 

 September. In 1988, 1.0% of fruit in the second-stage 



18 



Fruit Notes, Winter, 1991 



