Paper Title
Preliminary Study of the Insecticidal Activity of the Medicinal Plant Anastatica Hierochuntica Against Culex Pipiens Mosquito

Abstract
The insects Culicidae are probably the best known and the most feared for both parasitic diseases they can inoculate during their blood meal and the nuisance their presence constitutes. The distribution area of arthropods involved in the transmission of these diseases has continued to expand, placing new human populations in areas at risk of infection. In order to counter the spread of insects and epidemics arising there, several methods involving the use of chemical insecticides were tested. However, apart from their toxicity, some chemicals used in this fight have become less effective because of the resistance developed by some mosquitoes. Scientists then try to find other products accessible, less toxic (natural products especially who are known as bio-insecticides) to lead this fight. In this context, the use of natural molecules (of ecological and economic interest) with insecticidal or insect repellent properties proves to be alternative to the use of synthetic insecticides. The use of medicinal plants as insecticides has been known for a long time. In this study, we tested the larvicidal potential of Anastatica hierochuntica on the larvae of a species particularly replied, very common in cities Culex pipiens. The toxicological assays were carried out using the plant infusion, with different concentrations (15, 30, 60 and 100g/l), on the fourth instars larvae of Culex pipiens, for 24 hours, to determine the two lethal concentrations LC50 and LC90. Results, under laboratory conditions, indicate a variable sensitivity of the treated larvae; this sensitivity is even higher with increasing concentration of Anastatica hierochuntica. The lethal concentrations estimated are 39.87 g/l for LC50 and 228.58 g/l for LC90. Keywords - Bio-Insecticide, Culex Pipiens, Medicinal Plant , Anastatica Hierochuntica.