Table 2. Susceptibility (± 95% Confidence Interval) of western corn rootworm adults by contact to bifenthrin from field populations throughout Nebraska and Kansas, and from two non-diapause laboratory colonies.
Resistance ratios compared with lowest non-diapause LC50; bioassays conducted in 2014.
| Populations | N a | Slope (±SE) | LC50 (95% CI)μg/vial | RR50(95% CI) | LC90 (95% CI)μg/vial | RR90(95% CI) | X 2 (d.f.) |
|---|---|---|---|---|---|---|---|
| Non-diapause b | 210 | 4.77 (0.76) | 0.54 (0.46–0.64) | - | 1.01 (0.82–1.42) | - | 1.07 (5) |
| Non-diapause c | 240 | 2.55 (0.28) | 0.24 (0.16–0.37) | - | 0.77 (0.48–1.85) | - | 12.17 (6) |
| Clay Co (UNL)-NE * | 240 | 2.49 (0.28) | 0.98 (0.49–2.24) | 4.05 (2.97–5.53) | 3.20 (1.59–30.45) | 4.17 (2.53–6.89) | 22.03 (5) |
| Perkins Co 2-NE * | 240 | 1.95 (0.23) | 1.14 (0.89–1.49) | 4.72 (3.37–6.61) | 5.18 (3.49–9.32) | 6.75 (3.76–12.2) | 4.37 (5) |
| Keith Co 2-NE * | 240 | 1.94 (0.27) | 2.20 (1.32–5.12) | 9.13 (6.33–13.2) | 10.05 (4.54–98.99) | 13.10 (6.53–26.3) | 10.79 (5) |
| Chase Co 2-NE * | 110 | 2.24 (0.28) | 1.38 (0.80–2.96) | 5.75 (4.10–7.95) | 5.14 (2.54–39.65) | 6.70 (3.76–11.9) | 14.08 (5) |
| Finney Co 1-KS * | 210 | 2.41 (0.42) | 1.43 (0.85–2.32) | 5.94 (4.17–8.46) | 4.87 (2.84–20.75) | 6.35 (3.49–11.6) | 7.05 (5) |
| Sherman Co-KS * | 210 | 2.37 (0.28) | 0.97 (0.54–1.95) | 4.0 (2.92–5.49) | 3.35 (1.73–20.70) | 4.36 (2.58–7.37) | 16.13 (5) |
aTotal number of adults tested
bWCR lab colony from USDA/ARS North Central Agricultural Research Laboratory, Brookings, SD
cWCR lab colony from Crop Characteristics, Inc., Farmington, MN
*WCR field populations