within-orchard control of flies (Table 2) show 

 that 1995-version spheres as well as 1996- 

 version spheres provided a level of control 

 essentially identical to that provided by sticky 

 spheres (1.0% fruit injury or less). In contrast, 

 96 and 97% of fruit on unmanaged apple trees 

 and about 250 yards away was injured by apple 

 maggot flies in 1995 and 1996, respectively. In 

 1995, pesticide-treated spheres were dipped in 

 a 16% sucrose solution weekly after the fifth 

 week of exposure to renew feeding stimulant. 

 In 1996, no such dipping was performed. 



Conclusions 



Our findings show that 1996-version 

 pesticide-treated spheres (each with 14 sugar- 

 filled holes) maintained high season-long 

 residual activity against apple maggot flies and 



provided excellent control of this pest under 

 commercial orchard conditions. They have a 

 distinct advantage over earlier versions of 

 pesticide-treated spheres in requiring no re- 

 treatment with sucrose solution during the 

 growing season. Their major shortcoming is 

 the need to drill holes in each sphere and then to 

 fill each hole with sucrose/flour mixture 

 annually before painting. In the coming year, 

 we plan to determine the optimum number and 

 size of holes needed to attain season-long 

 sphere effectiveness and to determine if one 

 rather than two coats of paint will suffice. 



Acknowledgments 



This work was supported by a grant from 

 the USDA Northeast Regional IPM Competi- 

 tive grant and Hatch funds. 



ml0 mlm «£• mS^ %9^ 

 •^ r|% 0^ 0^ «^ 



Fruit Notes, Volume 62 (Number 2), Spring, 1997 



