Table 2 Concentration–response bioassays of GC and CEAS 300 Leptinotarsa decemlineata strains to dsRNA targeting the V-ATPase subunit A gene (dsRNA) and Cry3Aa protoxin from Bacillus thuringiensis (Cry3Aa) in leaf bioassays.

From: Selection for high levels of resistance to double-stranded RNA (dsRNA) in Colorado potato beetle (Leptinotarsa decemlineata Say) using non-transgenic foliar delivery

Strain

Treatment

LC50a (95% FL)

RRb

Slope ± SE

χ2 (df)c

GC

dsRNA

0.18 (0.09–0.29)

–

0.87 ± 0.11

19.589 (22)

Cry3Aa

4.22 (1.49–8.70)

–

1.34 ± 0.23

10.612 (8)

CEAS 300

dsRNA

 > 2000d

 > 11,100

–

–

Cry3Aa

17.57 (10.30–28.01)

4.2 (1.5–8.7)e

1.78 ± 0.38

5.086 (8)

  1. aLC50 values expressed in μg/ml.
  2. bResistance Ratio, estimated for dsRNA as the ratio of the LC50 value for GC to the highest dose tested without mortality for CEAS 300 (2,000 µg/ml); and for Cry3Aa protoxin as the lethal concentration ratio estimated by probit analysis in the POLO-PLUS program.
  3. cChi square (χ2) value and degrees of freedom (df) from fitting the data to the probit model.
  4. dNo significant mortality when compared to controls was detected at 2,000 µg/ml (highest dsRNA dose tested).
  5. eResistance ratio and 95% confidence intervals (in parenthesis) calculated using POLO-PLUS as described in Materials and Methods.
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