Table 3.
Concentration–response (MIC50; µg mL−1) of Diatraea saccharalis in diet‐incorporation bioassays with purified Cry1A.105 and Cry2Ab2 proteins
| D. saccharalis strain | n | Slope ± SE | MIC50 (95% CI)a | χ2 (df)b | Resistance ratioc |
|---|---|---|---|---|---|
| Tests with Cry1A.105 protein | |||||
| RR | 767 | 1.34 ± 0.09 | 57.89 (42.16–83.66) | 93.95 (6) | 186.74 |
| VM | 768 | 2.12 ± 0.14 | 0.48 (0.39–0.59) | 55.30 (6) | 1.55 |
| SS | 768 | 1.61 ± 0.11 | 0.31 (0.23–0.40) | 46.89 (6) | – |
| Tests with Cry2Ab2 protein | |||||
| RR | 672 | 2.29 ± 0.25 | 116.36 (89.04–116.41) | 25.80 (5) | 1.51 |
| VM | 637 | 2.04 ± 0.19 | 29.01 (23.42–36.29) | 116.15 (5) | 0.38 |
| SS | 668 | 1.54 ± 0.17 | 77.29 (56.50–115.74) | 39.97 (5) | – |
a
MIC50: concentration that inhibits molting to second instar in 50% of individuals after 7 days.
b
P < 0.0001 in the goodness‐of‐fit test.
c
Resistance ratio = (MIC50 of indicated strain)/(MIC50 of SS strain).