Table 1

Toxicity of permethrin to UCR-S and Pyr-R adult H. virescens

Parameter	Strain
Parameter	UCR-S	Ace-R^1-a	Pyr-R
n ^1-b	300^1-c	49^1-d	114^1-d
Slope	2.47 ± 0.24	3.01 ± 0.64	3.07 ± 0.65
EC₅₀ (μg/vial)^1-e	1.1	1.0	25.1
Confidence intervals (μg/vial)	0.9–1.3	0.7–1.3	18.1–34.7
Resistance ratio^1-f			23.5 (UCR-S)
			25.1 (Ace-R)

↵1-a Pyrethroid-susceptible strain containing Woodrow83 background (Gilbert et al., 1996).
↵1-b Number of adult H. virescens tested excluding control.
↵1-c All males tested.
↵1-d Males and females tested.
↵1-e P < .05 LC₅₀.
↵1-f EC₅₀ of Pyr-R divided by either EC₅₀ for UCR-S or Ace-R.