Three Years of the Massachusetts 

 Second-stage Apple IPM Pilot Project: 

 Blocks Receiving Apple Maggot Fly 

 Interception Traps 



Ronald J. Prokopy, Margaret Christie, Katharine Rankin, and 

 Cheryl Donovan 



Department of Entomology, University of Massachusetts 



One year ago in Fruit Notes [54(l):l-5], we re- 

 ported our results of the first two years (1987, 1988) of 

 our second-stage apple IPM pilot project in Massachu- 

 setts commercial orchards. Second-stage IPM employs 

 behavioral, ecological, and biological approaches to 

 pest management as a substitute for all insecticide and 

 miticide treatments after the last spray against plum 

 curculio in early June. The intent of second-stage IPM 

 practices is not only to provide an environmentally 

 safe, cost-effective approach to controlling summer 

 pests that directly attack apple fruit (apple maggot, 

 codling moth, summer leafrollers) but also to alleviate 

 insecticide and miticide toxicity to beneficial predators 

 and parasites of important foliar pests such as mites, 

 aphids, leafminers, and leafhoppers. Allowing more 

 natural enemies of foliar pests to flourish reduces the 

 need for pesticide treatment against foliar pests and 

 thereby lessens the rate (currently high) at which these 

 pests are developing resistance to pesticides. To em- 

 phasize further this latter goal, a major facet of second- 

 stage IPM is use, during April, May, and June, of 

 pesticides leastlikely to be harmful to beneficial preda- 

 tors and parasites. 



From a veiy real and timely, practical point of view, 

 under current strong public pressure to reduce pesti- 

 cide use on apples, perhaps one of our best hopes for 

 minimizing the risk of there being detectable pesticide 

 residues on apples at harvest lies in implementing the 

 philosophy and practices of second-stage IPM. This 

 philosophy of no insecticide or miticide spray on apples 

 after early June should be highly appealing to environ- 

 mentalists, legislators, public health officials, and con- 

 sumers. The big question is: can high quality fruit be 

 produced economically year after year under this phi- 

 losophy? 



Over the 3 years of our pilot project (1987-1989), 

 we have compared 2 different non-pesticidal ap- 

 proaches to implementing second-stage IPM philoso- 



phy. The essential difference between the two lies in 

 the techniques used for intercepting apple maggot flies 

 (a key summer pest) before flies can penetrate the 

 orchard interior during their movement toward or- 

 chards from abandoned host trees hundreds of yards 

 away. The techniques are: (1) placing synthetic-apple- 

 odor-baited sticky red sphere traps every 10 yards 

 (1987) or every 5yards (1988, 1989) on perimeter apple 

 trees and (2) spraying perimeter (border row) apple 

 trees every 3 weeks from late June through August. 

 For both approaches, we aimed to control codling 

 moths and summer leafrollers by removing (in May, 

 1987) all abandoned apple trees within 100 yards of the 

 orchard block perimeter to preclude immigration of 

 fruit-seeking female moths. Each approach has been 

 carried out over the 3-year pilot period in 6 commercial 

 orchard blocks, averaging 2 to 3 acres each. Each test 

 block has been matched with a nearby block of compa- 

 rable size that was treated during June, July, and 

 August under first-stage IPM practices. 



Here, we report results of the technique using 

 apple maggot fly interception traps. In a companion 

 article, we report results of the technique using pe- 

 rimeter row sprays. 



Apple Maggot 



Data in Table 1 show that each year, very large 

 numbers of apple maggot flies were captured on the 

 interception traps in the second-stage IPM blocks 

 (range of 2,054 to 3,180 flies per block per year). In our 

 judgement, this level represents an enormous amount 

 of potential maggot fly pressure on the crop. Even so, 

 a 3-year average of only 46% more flies was captured on 

 nonbaited monitoring traps at the interior of second- 

 stage compared with first-stage blocks. This reveals 

 the power of the traps in preventing fly immigration 

 into the block interior. 



Fruit Notes, Winter, 1990 



