Table 1.
Responses of H. zea to Cry1Ac and Cry2Ab toxins incorporated in diet
| 95% Fiducial limits |
|||||||
| Toxin | Strain | N | LC50 (µg⋅ml−1) | Lower | Upper | Slope | RR |
| Cry1Ac | LAB-S | 336 | 0.42 | 0.08 | 0.80 | 1.1 | 1.0 |
| GA | 560 | 23 | 14 | 44 | 1.0 | 55 | |
| GA-R | 560 | 230 | 140 | 480 | 0.9 | 560 | |
| Cry2Ab | LAB-S | 336 | 2.2 | 1.6 | 2.8 | 2.2 | 1.0 |
| GA | 336 | 31 | 21 | 54 | 1.5 | 14 | |
| GA-R | 336 | 62 | 30 | 340 | 0.9 | 28 | |
LAB-S, susceptible LAB-S; GA, field-derived strain from Georgia; GA-R, resistant strain derived from the GA strain and selected with Cry1Ac in the laboratory; N, number of larvae tested; RR, resistance ratio, the LC50 of a strain divided by the LC50 of the susceptible LAB-S strain.