Etude de la toxicité de certaines plantes sur les larves de culex pipiens (Diptera, Culicidae)

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. The resistance of these insects to chemical pesticides and bioaccumulation of toxic compounds in the environment have directed research towards of the bio-pesticides selective and biodegradable and especially extracts of aromatic plants. In this perspective we developed a study relating to the use of insecticides extracted from 10 herbs namely; Artemisia herba alba, Marrubium vulgare,Laurus nobilis, Eucalyptus globulus, Mentha spicata, Rosmarinus officinalis, Ruta montana, Thymus vulgaris, Lavandula officinalis and Origanum compactum on the larvae of a species particularly replied, very common in cities Culex pipiens L. Results show a variable sensitivity of the larvae; this sensitivity is even higher with increasing concentration of the extract. Furthermore, the toxicity is well marked when the exposure time of the larvae is longer. The extract of Artemisia herba-alba is the one that generates the highest mortality rate acting at relatively low concentrations.