toring traps in blocks surrounded by wooden pesticide- 

 treated spheres than in blocks sprayed with insecticide. 

 In 1997, blocks surrounded by sugar/ilour pesticide- 

 treated spheres or sticky spheres likewise received sig- 

 nificantly more flies on interior monitoring traps than 

 did sprayed blocks, but there were no significant dif- 

 ferences among these treatments m 1998 or 1999. Each 

 year, the rank order (most to least) in which blocks 

 received flies on interior monitoring traps was the same: 

 wooden-pesticide treated spheres, sugar/fiour pesti- 

 cide-treated spheres, sticky spheres, and insecticide 

 sprays. 



Assessment via fruit injury by AMF (Figure 2) 

 showed no significant differences among any of the 

 four treatments for any year except 1998, when sig- 

 nificantly more injury occurred to fruit in blocks sur- 

 rounded by wooden pesticide-treated spheres than in 

 blocks of any other treatment. Each year, the rank or- 

 der (most to least) in which blocks received injury was 

 the same: wooden pesticide-treated spheres, sugar/flour 

 pesticide spheres, sticky spheres and insecticide sprays. 

 The only exception was in 1999, when damage was 

 low in all treatments and there was no numerical dif- 

 ference in injury among the latter three treatments. 



Conclusions 



Our findings revealed a consistent pattern in abil- 

 ity of odor-baited red spheres to intercept AMF and 

 prevent injury to fruit. Each year, sticky-coated spheres 

 were slightly less effective than insecticide sprays. 

 Each year, sugar/flour pesticide-treated spheres were 

 only slightly less effective than sticky-coated spheres, 

 with comparative effectiveness essentially equal in 

 1999. Each year, wooden pesticide-treated spheres 

 were less effective than sugar/fiour pesticide treated 

 spheres, with comparative effectiveness being similar 

 in 1999. 



It is gratifying that 1999 versions of wooden and 

 sugar/fiour pesticide-treated spheres were more effec- 

 tive (relative to sticky spheres and insecticide sprays) 

 than 1997 or 1998 versions. Even so, further improve- 

 ments are needed. In the case of wooden pesticide- 

 treated spheres, an improved disc of wax and sucrose 

 atop spheres is needed to ensure a continuous replen- 

 ishing of sucrose to the sphere surface over the entire 

 3 -month season of sphere deployment. In the case of 



sugar/flour pesticide-treated spheres, there is need for 

 an inexpensive and more effective substitute for cay- 

 enne pepper for deterring feeding on spheres by ro- 

 dents. Cayenne pepper is prohibitively expensive at 

 concentrations greater than the 5% concentration used 

 here, which was ineffective. There is also need for the 

 private firm (Fruit Sphere Inc.) that has recently con- 

 tracted to manufacture sugar/fiour spheres to do so 

 using an extruder and/or injection moulder so as to 

 produce affordable spheres that are more uniform in 

 shape, size, and hardness than the spheres used here, 

 which were formed by hand. Ideally, manufactured 

 sugar/fiour spheres would remain completely intact 

 until autumn or winter, when freezing would cause 

 breakdown and disintegration. 



Before improved versions of wooden or sugar/flour 

 pesticide-treated spheres can be recommended for 

 broad usage as a substitute for insecticide sprays to 

 control AMF, such spheres need to be evaluated in 

 larger blocks of apple trees than used here and deploy- 

 ment patterns of spheres need to be optimized so as to 

 minimize the number of spheres per acre needed to 

 achieve reliable control. Factors such as composition 

 and arrangement of cultivars within orchard blocks, 

 tree size, and fruit color and density can affect degree 

 of sphere apparency to AMF, and hence can have a 

 strong bearing on the number and arrangement of 

 spheres needed for behavioral control. 



A ckn o wledgem en ts 



We thank the growers who allowed us to conduct 

 this research in their orchards: Wayne Rice, Dave 

 Shearer, Tim Smith, Tony Lincoln, Joe Sincuk, Bill 

 Broderick, Dave Chandler, and Dana Clark. We also 

 thank Baruch Shasha, J.L. Willet, and R.W. Behle for 

 assistance in constructing pesticide-treated spheres in 

 1997, The Biotechnology Research and Development 

 Corporation for producing spheres used in 1999, and 

 Bradley Chandler and Stephen Lavallee for assistance 

 in evaluating sphere performance in orchards. This 

 work was supported by grants from the Massachusetts 

 Society for Promoting Agriculture, the Massachusetts 

 Department of Food & Agriculture, the USDA 

 CSREES Pest Management Alternatives Program, the 

 USDA SARE Program, and the Washington State Tree 

 Fruit Research Commission. 



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Fruit Notes, Volume 64 (Number 4), Fall, 1999 



17 



