Table 1. Dose-mortality response of S. frugiperda strains to lambda-cyhalothrin and chlorpyrifos.
| Insecticide | Strain | na | Slope(±SE) | LD50 b(95% CI) | RRc(95% CI) |
| Chlorpyrifos | SUS | 611 | 1.31(±0.10) | 19.78(17.48–22.15) | - |
| OP | 588 | 2.81(±0.211) | 357.03(263.77–486.99) | 18.1(15.4–21.1) | |
| Lambda-cyhalothrin | SUS | 720 | 1.63(±0.108) | 0.30(0.20–0.42) | - |
| PYR | 624 | 3.11(±0.215) | 8.47(6.72–10.52) | 28.2(23.2–34.4) |
a
number of larvae tested.
b
µg of insecticide/g of insect.
c
LD50 of resistant strains/LD50 of the SUS strain.