Table 4. Values of 50% lethal concentration (LC₅₀) in Tangkou population of Culex pipiens pallens in response to deltamethrin selection.

Treatment	Generation	LC50 (ppm)	95% confidence interval	Slope	Resistance ratio*
	Parental (G0)	0.0204	0.0144–0.0289	1.2179	1.00
Selection	G6	0.0565	0.0413–0.0774	1.5672	2.77
	G12	0.5761	0.4858–0.6832	2.5899	28.24
Control	G6	0.0101	0.0084–0.0121	2.3149	0.49
	G12	0.0098	0.0081–0.0118	2.2160	0.48

*Resistance ratio is the ratio of LC₅₀ of the test population to LC₅₀ of the initial parental (G₀) population.