Table 2.
Concentration-mortality response (LC; µg a.i./cm2) of larvae and adults of A. diaperinus from southern Brazil exposed to cypermethrin
| Pop. code | n | Slope ± SEa | LC50 (95% CI)a,b | χ2c | dfd | Resistance ratioe |
|---|---|---|---|---|---|---|
| Larvae | ||||||
| Lab | 186 | 1.10 ± 0.24 a | 0.43 (0.27–0.72) a | 2.28 | 4 | – |
| RS-1 | 182 | 1.36 ± 0.29 ab | 0.50 (0.24–1.13) a | 1.45 | 4 | 1.2 |
| RS-2 | 210 | 1.06 ± 0.12 a | 0.45 (0.21–0.79) a | 6.86 | 4 | 1.0 |
| RS-3 | 183 | 1.80 ± 0.19 b | 1.70 (1.29–3.28) b | 2.83 | 4 | 3.9 |
| SC-1 | 290 | 1.11 ± 0.25 a | 7.33 (4.13–11.87) c | 5.43 | 5 | 17.0 |
| SC-2 | 210 | 1.19 ± 0.19 a | 2.22 (1.95–2.94) b | 3.70 | 4 | 5.2 |
| SC-3 | 187 | 1.09 ± 0.18 a | 5.87 (4.81–8.71) c | 3.67 | 4 | 13.6 |
| PR-1 | 183 | 1.67 ± 0.17 ab | 1.72 (1.20–2.32) b | 1.01 | 4 | 4.0 |
| PR-2 | 180 | 1.47 ± 0.12 ab | 1.84 (1.14–2.45) b | 4.07 | 4 | 4.3 |
| Adults | ||||||
| Lab | 150 | 1.39 ± 0.42 abc | 0.46 (0.27–0.88) a | 5.25 | 4 | – |
| RS-1 | 133 | 1.64 ± 0.22 b | 1.23 (0.40–1.72) ab | 1.05 | 4 | 2.7 |
| RS-2 | 210 | 1.16 ± 0.16 a | 0.77 (0.38–1.02) ab | 3.59 | 4 | 1.7 |
| RS-3 | 184 | 1.85 ± 0.19 c | 0.71 (0.28–1.05) ab | 2.50 | 4 | 1.6 |
| SC-1 | 242 | 1.06 ± 0.17 a | 2.09 (0.92–3.93) bc | 2.72 | 4 | 4.5 |
| SC-2 | 181 | 1.57 ± 0.50 abc | 1.43 (0.99–1.64) b | 6.05 | 4 | 3.1 |
| SC-3 | 187 | 3.18 ± 0.68 d | 4.93 (3.11–6.62) c | 1.09 | 4 | 10.7 |
| PR-1 | 185 | 1.54 ± 0.12 bc | 3.99 (2.88–6.24) c | 5.01 | 4 | 8.7 |
| PR-2 | 214 | 1.02 ± 0.18 a | 2.45 (1.78–3.60) bc | 6.76 | 4 | 5.3 |
aLC50 values designated by different letters within a column are significantly different from each other through nonoverlap of 95% confidential intervals. Significance of differences among slopes determined by likelihood ratio test of equality followed by pairwise comparisons using nonoverlapping fiducial limits.
bLC50: concentration of cypermethrin (µg a.i./cm2) required to kill 50% of insects in the observation period of 48 h.
c P > 0.05 in the goodness-of-fit test.
dDegrees of freedom.
eResistance ratio = (LC50 of indicated population)/(LC50 of Lab population).