Larvicidal activity of an Algerian Ruta graveolens essential oil on mosquito species Culex pipiens

Abstract

Background: to assess the mosquito larvicidal potentials of essential oil of Ruta graveolens (Sapindales: Rutaceae) against larvae of Culex pipiens (Diptera: Culicidae), a mosquito species of medical importance, to examine its effect on morphometric parameters (weight and body volume) and caloric indexes (proteins, carbohydrates and lipids) of third and fourth instar. Materials and Methods: Larvicidal efficiency of essential oil obtained from the leaves of Ruta graveolens was tested at various concentrations between 3 and 20ppm on the third stage larvae, between 5 and 25ppm on fourth stage larvae of Culex pipiens under standard laboratory conditions according to the recommendations of the World Health Organization. Bioassay test was carried out by WHO 2005; the 24h LC25, LC50 and LC90 values was determined by probit analysis. Results: The mortality recorded after 24 hours of exposure showed an excellent larvicidal activity with a concentration-response relationship and with LC50 values of 9.95 and 11.77ppm for L3 and L4 of Culex pipiens respectively. Ruta graveolens essential oil with both concentrations (LC25 and LC50) cause a significant reduction in weight, volume, biochemical compositions and caloric indexes of the third and fourth instar larvae of Culex pipiens. Conclusion: These results would be useful to replace chemical larvicides with bioactive compounds from plant sources such as a new mosquito control agents.