Nicotiana tabacum a prospective mosquitocide in the management of Anopheles gambiae (Giles)

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.