The influence of age on insecticide susceptibility of Anopheles arabiensis during dry and rainy seasons in rice irrigation schemes of Northern Tanzania

Table 2 Knock-down time and mortality rates of Anopheles arabiensis exposed to Lambda-cyhalothrin for a period of 60 min in dry and rainy seasons

Age (days)	Season	Number tested	24 h mortality	95% CI	KDT₅₀	95% CI	KDT₉₅	95% CI	KDT₅₀ ratio (RR)
2	Dry	800	40.4	36.1–44.7	51.36	49.2–53.7	126.3	118.6–135.1	3.4
2	Rain	800	76.0	73.7–78.3	18.82	18.1–19.6	46.07	44.8–49.2	1.4
3	Dry	800	43.1	28.8–57.4	57.10	54.6–59.7	140.4	131.5–150.7	3.8
3	Rain	800	81.0	78.7–83.3	33.35	32.2–34.3	83.1	79.4–87.1	2.4
5	Dry	800	79.6	57.0–102.2	50.33	48.1–52.6	123.7	116.2–132.3	3.3
5	Rain	800	91.8	88.9–94.6	26.39	25.4–27.4	53.7	51.5–56.2	1.9
10	Dry	800	81.7	66.7–96.6	23.9	22.9–25.0	58.9	55.7–62.5	1.6
10	Rain	800	97.8	96.5–99.1	34.14	32.9–35.3	84.9	81.2–89.1	2.5
Control^a	Dry	800	100	–	15.1	–	27.6	–	–
Control^a	Rain	800	100	–	13.7	–	27.3	–	–

ISSN: 1475-2875