treatments among the available 72 fruiting trees. 



Although there were no significant differences 

 among spheres topped by different sizes of discs in 

 total AMF captured, data in Table 1 are suggestive of 

 some trends. The three types of spheres capturing the 

 fewest AMF were control spheres without discs and 

 spheres topped by discs of 1.5-inches diameter. As a 

 group, these spheres captured only 60% as many total 

 AMF as spheres topped by discs of 2.4-inches diameter 

 and only 67% as many total AMF as spheres topped 

 by discs of 3-inches diameter (Figure 2). Also, as a 

 group, spheres topped by discs of 1.2-inches height 

 captured about 6% and 14% more total AMF than 

 spheres topped by discs of y4-inch and 1 .5-inch height, 

 respectively (Figure 2). 



With respect to capture of AMF on the top half 

 versus the bottom half of spheres, data in Table 1 show 

 the following: for spheres having discs of y4-inch, 1 .5- 

 inch, and 3-inch diameter: 55, 53, and 62%, 

 respectively, of all captured AMF were found on the 

 bottom half of spheres. 



on fly captures. Somewhat more AMF were captured 

 on the bottom half than the top half of spheres. 



Together, these findings bode well for future use 

 of sugar/wax discs that are larger than the 2-inch 

 diameter x y4-inch tall discs we used in our 2001 

 laboratory and field tests. It appears that we could 

 increase the size of sugar/wax discs to 3 inches in 

 diameter x 1 .2 or 1 .5 inches in height and by doing so 

 actually enhance sphere attractiveness to AMF. 

 Furthermore, our findings here that most AMF alight 

 on the bottom half of spheres suggest that post-alighting 

 AMF would have increased probability of encountering 

 sugar on the sphere surface, which tends to collect more 

 on the bottom half of spheres. Finally, information 

 from another test revealed that all 50 AMF observed 

 alighting on spheres topped by sugar/wax discs (2- 

 inches diameter x y4-inch tall) did so on the spheres 

 themselves and not on the discs. This ensures that 

 alighting AMF would encounter pesticide and sugar 

 on the sphere surface rather than pesticide-free sugar 

 discs atop spheres. 



Conclusions 



A ckn o yvledgem ents 



To our pleasant surprise, spheres topped by discs 

 of 2.4 or 3 inches in diameter caught more total AMF 

 than spheres without discs or spheres topped by discs 

 of 1.5-inch diameter. Height of disc had little effect 



We thank Jaime Pinero and Sara Dynok for 

 assistance. This study was supported by grants from 

 the USDA CSREES Pest Management Alternatives 

 Program and Crops at Risk Program. 



*^f^ %1^ %S^ %1^ 

 ^J^ #y% #1^ ^J^ 



Fruit Notes, Volume 66, 2001 



39 



