Adult mosquitoes of the sibling species Anopheles gambiae and Anopheles coluzzii exhibit contrasting patterns of susceptibility to four neonicotinoid insecticides along an urban-to-rural gradient in Yaoundé, Cameroon

Table 1 Lethal concentrations, LC₅₀ and LC₉₉, estimated at 24 h and 72 h post-exposure

Active ingredient	Species	Number of mosquitoes	Holding period (h)	LC₅₀ value (µg/L)	Lower–upper 95% confidence intervals (µg/L)	Standard error	LC₉₉ value (µg/L)	Lower–upper 95% confidence intervals (µg/L)	Standard error	Chi square	p value
Acetamiprid	An. gambiae (Kisumu)	500	24	13.60	11.50–15.50	1.08	69.00	54.40–98.10	1.16	18.10	< 0.001
Acetamiprid	An. gambiae (Kisumu)	500	72	13.90	11.30–16.20	1.07	64.10	48.70–101.00	1.15	24.30	< 0.001
Imidacloprid	An. gambiae (Kisumu)	350	24	18.60	15.20–22.00	1.10	152.00	112.00–235.00	1.20	18.40	< 0.001
Imidacloprid	An. gambiae (Kisumu)	350	72	17.10	12.90–21.40	1.10	148.00	100.00–273.00	1.21	22.00	< 0.001
Thiamethoxam	An. coluzzii (Ngousso)	475	24	9.66	6.78–13.50	1.14	133.00	79.40–277.00	1.26	25.70	< 0.001
Thiamethoxam	An. coluzzii (Ngousso)	475	72	7.47	5.84–9.67	1.13	75.30	47.8–142.00	1.31	13.20	< 0.001

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