Vol. 2, Issue 4, Part A (2015)

Author(s): Kayode David Ileke, Emmanuel Ayobami Oyeniyi, Olaniyi Charles Ogungbite, Jacobs Mobolade Adesina

Abstract: The mosquitocidal potential of leaf and seed extract of Nicotiana tabacum in the management of larvae, pupae and adults of Anopheles gambiae was assessed at five different concentrations (0.1%, 0.2%, 0.3%, 0.4% and 0.5%) at ambient temperature (28±2 ⁰C) and relative humidity (75±5%). Larvicidal and pupacidal activity of both extracts was assessed after 24 h while adulticidal activity was recorded at 3 h post-treatment. Results showed that both extracts of N. tabacum elicited 100% mortality in larvae, pupae and adults of An. gambiae at the highest experimental concentration. Regardless of the stage of An. gambiae, LC₅₀ values revealed that leaf extract showed more toxicity than the seed extract. The LC₅₀ values of leaf and seed extract of N. tabacum also increased with the developmental stages of the mosquitoes with the lowest and highest observed in larval (leaf: 0.153µg/ml; seed: 0.188µg/ml) and adult (leaf: 0.219 µg/ml; seed: 0.290 µg/ml) stage respectively. Median LC₅₀ values were however observed in pupae of An. gambiae (leaf: 0.176 µg/ml; seed: 0.213µg/ml). Various results obtained from this study therefore showed that N. tabacum extract could serve as a means of controlling mosquitoes causing malaria disease in Nigeria.