Journal of Tropical Medicine

Research Article

Larvicidal, Ovicidal, and Repellent Activities of Leucas stachydiformis (Hochst. ex Benth.) Briq Essential Oil against Anopheles arabiensis

Table 2

Larvicidal activity of the essential oil of Leucas stachydiformis against fourth instar Anopheles arabiensis larvae.


Concentration (ppm)	Mortality % ± SD			LC₅₀ (95% CI) ppm	LC₉₀ (95% CI) ppm	Chi-square
Concentration (ppm)	24 h	48 h		LC₅₀ (95% CI) ppm	LC₉₀ (95% CI) ppm	Chi-square

400	92 ± 0.5	96 ± 0.7		43.4	229.7	6.3
200	88 ± 1.2	92 ± 1.5	24 h	(31.8–58.5)	(151.6–430.9)
100	72 ± 0.9	72 ± 1.3
50	56 ± 1.3	68 ± 1.1
25	52 ± 2.5	60 ± 1.8		34.2	175.7	8.3
12.5	8 ± 0.6	8 ± 1.6	48 h	(25.0–45.7)	(118.3–317.9)
6.25	4 ± 0.2	8 ± 0.5
Negative control	0 ± 0.0	0 ± 0.0

Values were based on seven concentrations and four replications with 25 larvae in each. Chi-square values were significant at level. LC₅₀, 50% lethal concentration; LC₉₀, 90% lethal concentration; CI, confidence interval; negative control, 2% dimethyl sulfoxide (DMSO).