Table 2 Resistance status of Aedes aegypti (USDA and IPL strains) against temephos and potential alternative insecticides. Numbers in bold correspond to a resistance ratio (RR) statistically different from 1. RR between 2 and 10 show a moderate resistance to the insecticide according to WHO criteria
Larvicide | Strain | No. of larvae | LC50 (95% CI) (μg/l) | LC95 (95% CI) (μg/l) | RR50 | RR95 | χ 2 | P | Slope ± SE |
|---|---|---|---|---|---|---|---|---|---|
Bti | USDA | 1501 | 14 (12–21) | 54 (31–199) | – | – | 0.2 | 0.89 | 2.8 ± 0.6 |
IPL | 1600 | 11.8 (11.3–12.3) | 21 (19–23) | 0.8 | 0.4 | 5.5 | 0.24 | 6.6 ± 0.5 | |
Diflubenzuron | USDA | 1500 | 1.7 (1.5–1.8) | 5.6 (4.6–7.2) | – | – | 8.5 | 0.075 | 3.1 ± 0.3 |
IPL | 804 | 1.8 (1.4–2.1) | 4.1 (3.8–6.8) | 1.1 | 0.7 | 20.0 | 0.0005 | 4.6 ± 0.3 | |
Pyriproxyfen | USDA | 1500 | 0.086 (0.05–0.1) | 0.049 (0.03–0.06) | – | – | 4.4 | 0.11 | 1.4 ± 0.3 |
IPL | 699 | 0.019 (0.017–0.022) | 0.098 (0.074–0.12) | 0.2 | 2.0 | 7.6 | 0.055 | 2.4 ± 0.2 | |
Spinosad | USDA | 1500 | 14 (12–19) | 40 (26–96) | – | – | 0.4 | 0.79 | 3.6 ± 0.3 |
IPL | 1472 | 69 (62–77) | 206 (170–270) | 4.9 | 5.2 | 3.4 | 0.18 | 3.4 ± 0.3 | |
Temephos | USDA | 1250 | 2.9 (2.7–3.1) | 6.6 (5.8–7.6) | – | – | 3.7 | 0.59 | 4.6 ± 0.3 |
IPL | 2600 | 6.6 (6.2–6.9) | 11.6 (10.5–13.5) | 2.3 | 1.8 | 5.3 | 0.07 | 6.6 ± 0.5 |