Environmental control of malaria: Can Citrus sinensis peel be a potent larvicide for household vector control?

The quest for alternatives to chemical-based insecticides has raised inquiries on various plant products for their potential efficacy in killing or repelling mosquitoes and eco-friendliness. However, as research inquiries build up, populations in endemic areas are still vulnerable to active malaria transmission maintained by competent vectors. Practical solutions deriving from research inferences should constantly be delivered by easy and affordable means to vulnerable populations. This study assessed the larvicidal efficacy of aqueous extract of Citrus sinensis, to determine the potentiality of developing a cheap, effective, and eco-friendly product from a local plant for environmental control of the malaria mosquito. Weighed quantities, 50g, 100g, 150g and 200g of fresh orange fruit (Citrus sinensis) peels were respectively subjected to low heating in 100ml of distilled water for 30 minutes and allowed to soak for 24 hours, to obtain stock aqueous extract of 0.5g/ml, 1.0g/ml, 1.5g/ml and 2.0g/ml concentrations, respectively.  Thirty 4th instar larvae of Anopheles species maintained in 100ml of natural breeding source water were treated with the extracts. Twenty four (24)-hour exposure produced concentration-dependent mortality of mosquito larvae (p < 0.05). Percentage mortality ranged between 65.57% and 100%, with 2.0g/ml concentration at all test volumes causing 100% mortality. The results suggest that aqueous extract of C. sinensis could be a potent eco-friendly mosquito control agent. This study documents the feasibility and effectiveness of a simple extraction method applicable at home for local and massive community-based malaria vector control. However, field trials of this simple procedure would ascertain the extent of achievable success.