Table 2. Insecticidal activity of neonicotinoids to susceptible aphids and the Kushima clone with and without pretreatment with piperonyl butoxide (PBO).

Compound	Susceptible clone		Kushima clone		RFa)	SFb)
	LC50 (ppm)	95% confidence limit of LC50	LC50 (ppm)	95% confidence limit of LC50
Acetamiprid	0.10	0.080–0.12	6.54	4.62–9.73	65.4
Thiacloprid	0.30	0.20–0.61	7.15	4.40–11.8	23.8
Imidacloprid	0.35	0.20–0.85	75.7	44.7–193	216
Clothianidin	0.10	0.061–0.18	39.4	28.0–58.5	394
Thiamethoxam	0.19	0.12–0.31	56.0	40.6–73.7	295
Dinotefuran	0.66	0.40–1.04	167	114–285	253
Nitenpyram	0.30	0.19–0.54	71.0	27.5–103	237
Acetamiprid+PBO	0.028	0.016–0.048	1.91	1.03–3.08		3.4
Imidacloprid+PBO	0.050	0.032–0.079	7.01	3.46–12.0		11

Experiments were performed in duplicate. ^a) Resistance factor (LC₅₀ Kushima clone/LC₅₀ susceptible clone). ^b) Synergistic factor (LC₅₀ Kushima clone/LC₅₀ Kushima clone with PBO).