Table 2.

Knock-down concentrations (KC_50s) and resistance ratios (RR_KC50) of adults of Aedes albopictus strains against deltamethrin and permethrin.

Insecticide	Strain	n	KC50 (95% CI) (µg/ml)	Fit of probit line				RRKC50 (95% CI)
				Slope (S.E)	χ2	df	p£
Deltamethrin	Ref-S	525	1.42 (0.94–2.25)	2.33 (0.20)	7.83	4	0.10	1
	Multan	525	4.35 (3.27–6.25)	1.92 (0.17)	5.47	4	0.24	3.06 (2.40–3.90)*
	Sahiwal	525	4.97 (3.70–7.35)	1.83 (0.17)	5.15	4	0.27	3.50 (2.70–4.51)*
	Lahore	450	13.91 (9.58–27.98)	2.06 (0.24)	3.96	3	0.27	9.80 (7.29–13.12)*
	Sheikhupura	525	18.55 (15.36–23.35)	1.96 (0.19)	1.81	4	0.77	13.06 (10.07–16.88)*
	Kasur	525	8.55 (6.54–11.40)	1.85 (0.16)	4.67	4	0.32	6.02 (4.75–7.60)*
	Faisalabad	525	12.69 (10.31–16.18)	1.53 (0.15)	1.21	4	0.88	8.94 (6.80–11.70)*
	Sialkot	525	7.13 (5.75–9.22)	1.54 (0.16)	3.14	4	0.54	5.02 (3.79–6.63)*
	Rawalpindi	450	4.82 (4.13–5.64)	2.23 (0.20)	1.64	3	0.65	3.39 (2.72–4.21)*
Permethrin	Ref-S	525	0.60 (0.40–0.90)	2.41 (0.22)	6.69	4	0.15	1
	Multan	450	7.28 (6.06–8.81)	1.82 (0.19)	2.61	3	0.46	12.13 (9.56–15.45)*
	Sahiwal	525	7.96 (6.64–9.66)	1.68 (0.14)	2.49	4	0.65	13.27 (10.44–16.92)*
	Lahore	450	6.85 (5.75–8.34)	1.99 (0.21)	0.70	3	0.87	11.42 (9.00–14.53)*
	Sheikhupura	525	8.50 (6.81–11.21)	1.55 (0.15)	1.27	4	0.87	14.19 (10.62–18.97)*
	Kasur	525	12.24 (9.69–16.20)	1.32 (0.13)	1.40	4	0.84	20.40 (15.19–27.50)*
	Faisalabad	525	8.69 (6.98–11.10)	1.33 (0.13)	1.69	4	0.79	14.48 (11.00–19.13)*
	Sialkot	525	15.47 (11.99–21.38)	1.28 (0.14)	2.59	4	0.63	25.78 (18.69–35.69)*
	Rawalpindi	525	12.99 (10.58–16.54)	1.56 (0.15)	1.07	4	0.90	21.65 (16.57–28.40)*

RR_KC50, resistance ratio at KC₅₀ = (KC₅₀ of a field strain) ÷ (KC₅₀ of Ref-S).

*significantly different from Ref-S based on 95% CIs of RR_KC50 did not include 1³⁹.