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hung from highbush blueberry branches, we found that the flies 

 were more attracted to yellow enamel ones than to enamel green, 

 blue, orange, red, white, gray, black, aluminum foil, or clear 

 Plexiglas ones. We then found that the maggot flies were even more 

 attracted to daylight fluorescent yellow rectangles than to enamel 

 yellow ones. These color responses of blueberry maggot flies were 

 virtually identical to the color responses of apple maggot flies 

 in earlier tests (see Sept. -Oct., 1976 issue of Fruit Notes ) . We 

 believe that the reason the flies are so attracted to bright yellow 

 color is because they perceive yellow as if it were super-bright or 

 super- intense foliage on which to find food. 



In another test, we hung 1.3 and 3- inch diameter red spheres 

 and found the blueberry maggot flies highly attracted to both, but 

 especially to the 3-inch ones. This is very similar to our findings 

 on apple fly response to red spheres (see Nov. -Dec, 1976 issue of 

 Fruit Notes ) . We believe that the reason the flies are so attrac- 

 ted to 3-inch red spheres is because they perceive such spheres as 

 if they were super-large blueberries on which to find mates or lay 

 eggs. 



We then coated 6 of the 6x8 inch daylight fluorescent yel- 

 low rectangles and 6 of the 3-inch red spheres with Bird Tangle- 

 foot (a clear sticky substance that captures and holds arriving 

 flies) and hung them from highbush blueberry branches in a planta- 

 tion in Munson, Mass. from July 13 to August 11. We caught a total 

 of 1547 blueberry maggot flies on the rectangles and 3309 on the 

 spheres. When ammonium acetate crystals (an odoriferous bait attrac- 

 ting food-seeking flies) was added to a second set of 6 yellow rec- 

 tangles, 2206 maggot flies were captured. This was more than on 

 the unbaited yellow rectangles, but fewer than on the unbaited 

 spheres . 



These findings indicate the sticky-coated daylight fluorescent 

 yellow rectangles and 3-inch red spheres are effective traps for 

 capturing large numbers of blueberry maggot flies. Hence, they can 

 be profitably employed to monitor maggot fly population levels and 

 activities in commercial plantings. Their use will aid in better 

 timing of maggot fly sprays, and avoidance of unnecessary applica- 

 tions when no maggot flies are present. 



Proper positioning of the traps is critical to their fly-cap- 

 turing effectiveness. They must be hung so that the flies can 

 clearly see them. Therefore, all foliage, twigs, and berries within 

 8-12 inches of all sides of each trap should be removed. But be- 

 yond this distance, there should be as much fruit and foliage as pos- 

 sible (especially below and to the sides) to attract flies into the 

 general area. Although we have not yet established any firm rela- 

 tionship between maggot fly trap captures and fruit infestation 

 levels, we would suggest that capture of 5 flies per trap per week 

 may warrant insecticide treatment on highbush berries grown for 



