-15- 



equally effective (compared with baited yellow rectangle traps) 

 at detecting early season AMF to being consistently more effec- 

 tive in capturing the first AMF. This result pattern is contrary 

 to that obtained in unsprayed, abandoned orchards where first cap- 

 tures usually occur on baited yellow rectangles. The difference 

 may be due to the fact that first- captured AMF in unsprayed orchards 

 are likely to be newly emerged and probably more apt to respond 

 to feeding stimuli. Hence, they are attracted to yellow rectangles 

 mimicking the reflectance of leaves (the feeding site). First- 

 captured AMF in commercial orchards are usually sexually mature 

 (immigrating to commercial orchards from abandoned trees or orchards) 

 They respond somewhat to feeding stimuli, but even more so to egg 

 laying stimuli, thus being attracted to fruit -mimicking red spheres. 



Trap Positioning 



We conducted 2 experiments aimed at defining an effective, 

 within-tree position for the red sphere trap. In the first, we 

 evaluated the influence of spatial distribution of fruit within a 

 1 meter radius around a sphere. The 3 treatments were: fruits 

 solely above a sphere; fruits solely below a sphere; and fruits 

 both above and below a sphere. In the second experiment, we eval- 

 uated the influence of distance of sphere from nearest surrounding 

 fruit alone and from nearest surrounding fruit and foliage combined. 

 The treatments were: spheres cleared of all foliage to a standard 

 distance of 25 cm, with surrounding fruit cleared to a distance 

 of cm, 25 cm, 50 cm, or 100 cm (1 meter); and spheres cleared 

 of surrounding fruit as well as foliage to these same distances. For 

 all treatments, spheres were hung about 2 meters above ground, toward 

 the outside of the tree canopy. 



TABLE 2. 



Within-tree position Mean number captured 



of red sphere trap AMF per sphere 



Location of fruit relative to sphere 



Above 11.4 



Below 16.0 



Above and below 14.6 



Distance of sphere from nearest 



surrounding fruit 



cm 6.9 



25 cm 16.1 



50 cm 17.1 



100 cm 8.5 



Distance of sphere from nearest 



fruit and foliage 



cm 2.7 



25 cm 14.2 



50 cm • 19.5 



100 cm 1-3 



15 replicates per treatment 



