Table 1.
The relative ratios (%) of the seven key essential volatile compounds used in three synthetic blends.
Figure 1.
Response of female P. viteana to doubling the ratio of a single volatile constituent.
Flight responses (% ±1 SE) of female P. viteana (N = 241) in the flight tunnel to hexane control, 7-component “optimized blend”, and six ratio-modified synthetic blends. Ratio modification was done systematically by doubling one compound in the optimized blend singly and is indicated by “x2” in the figure legend. Partial upwind flight was recorded when P. viteana made more than 50 cm of zig-zag upwind flight toward the target. Full upwind flight was the upwind flight to within 10 cm of the target. An average of 30 individual moths was flown to each target tested. tDMNT: 4,8-dimethyl-1,3(E),7-nonatriene.
Figure 2.
Effect of Japanese beetle foliar damage on female P. viteana flight response to host plant.
Flight responses (% ±1 SE) of female P. viteana (N = 84) in the flight tunnel to Japanese beetle damaged vs. undamaged V. riparia shoots. Partial upwind flight was recorded when P. viteana made more than 50 cm of zig-zag upwind flight toward the target. Full upwind flight was the upwind flight to within 10 cm of the target.
Figure 3.
GC-MS analysis of headspace volatiles from Japanese beetle damaged vs undamaged grapevines.
Modulation in the (A) concentration (as the sum of ion abundances from GC/MS analyses ± SE) and (b) ratio (% ±1 SE) of the 7 key volatile compounds emitted from Japanese beetle damaged vs. undamaged V. riparia shoots (N = 8). Z-LO: (Z)-linalool oxide; E-LO: (E)-linalool oxide; tDMNT: 4,8-dimethyl-1,3(E),7-nonatriene.
Figure 4.
Response of female P. viteana to modulations in ratio and concentration.
Partial and full upwind flight responses (% ±1 SE) of female P. viteana (N = 262) to three different synthetic blends (optimized blend vs. Japanese beetle undamaged blend vs. Japanese beetle damaged blend in Table 1) at two doses, (A) containing 30 µg of the 7 compounds per lure and (B) containing 300 µg of the 7 compounds per lure. Partial upwind flight was recorded when P. viteana made more than 50 cm of zig-zag upwind flight toward the target. Full upwind flight was the upwind flight to within 10 cm of the target. Different letters (capital letters for partial upwind flight response and small letters for full upwind flight response) on bars indicate significant differences (P<0.05).