"Evaluation de Metarhizium anisopliae à titre d'agent de lutte biologique contre les larves de moustiques"

Abstract

"In the search for alternative methods to chemical control, the use of the biopesticides is developed more and more against mosquitoes vectors of infectious diseases. The strains of fungus are most promising from this new point of view. In this study, we did a biological test of the local entomopathogenic fungi isolated from agricultural soils of Constantine. Based on morphological properties and 18S rRNA gene sequence analysis, For isolates were identified to the following species Metarhizium anisopliae . The susceptibility of Culex pipiens larvae to the entomopathogenic fungi Metarhizium anisopliae was examined under laboratory conditions. Five doses were used D1= 105 spores/ml, D2= 106 spores/ml, D3= 107 spores/ml, D4= 108spores/ml and D5= 109 spores/ml. we have tested the efficiency of for strains of Metarhizium anisopliae on the LD50 and LT50. Results obtained demonstrate that larvae mortality increased with increasing concentration and time of exposure to treatment. The evaluation of larvicidal activity of Metarhizium anisopliae against Culex pipiens larvae depicted as a good biocontrol agent. From Metarhizium anisoplae strains, twelve molecules have been purified and identified by means of several chromatographic (HPLC) and spectroscopic techniques (LC/MS and LC/MS/MS), It is a toxin (destruxins). All molecules exhibit insecticidal activities against mosquito larvae."